Developer Tools APIs
Developer tools here cover the plumbing around building software rather than any single data domain: fake REST endpoints and test data, package registry metadata, sandboxed code execution, WHOIS and DNS lookups, scraping services and SERP APIs. Many of the mock and registry APIs are free and need no key, like JSONPlaceholder and the npm Registry, while scraping and search APIs such as SerpApi are freemium and keyed.
| API | Pricing | Auth | Format | Free tier | Status |
|---|---|---|---|---|---|
AbacusKey/value counter service for tracking page hits or custom events with a single GET request, no key needed. Developer Tools › Monitoring | Free | None | JSON | <100/day | Live |
AddressMockGenerates format-correct sample addresses (street, city, ZIP, phone) for 7 countries, for testing forms. Developer Tools › Mock & Test APIs | Free | None | JSON | Unlimited | Live |
Agent NexusSearchable registry of APIs, MCP servers, and CLIs that AI agents can call, with live health data. Developer Tools › API Directories | Freemium | API key | JSON | 100–1k/day | Live |
AgentDealsSearch and compare developer tool free tiers, startup credits, and recent pricing changes. Developer Tools › API Directories | Free | None | JSON | Unlimited | Live |
Airport GapAirport records by IATA code, airport-to-airport distances and a favourites store for practising API tests. Developer Tools › Mock & Test APIs | Free | None | JSON | 10k+/day | Live |
Amazon Scraper APIStructured JSON for Amazon product, search and review data across 20 marketplaces; pay per success. Developer Tools › Web Scraping | Freemium | API key | JSON | — | Live |
AnyAPIPay-per-request gateway to hundreds of scraping and data APIs with automatic provider failover. Developer Tools › Web Scraping | Free trial | API key | JSON | — | Live |
Anycrap35,000+ AI-generated absurdist product concepts with names, descriptions and images for mock data. Developer Tools › Mock & Test APIs | Free | API key | JSON | — | Live |
API LeagueSingle-key hub bundling separate APIs for jokes, news, books, recipes, games and art search. Developer Tools › API Directories | Freemium | API key | JSON | <100/day | Live |
API Status CheckIndependent uptime and outage status for 190+ developer APIs like OpenAI, Stripe, AWS and GitHub. Developer Tools › Monitoring | Freemium | None | JSON | 1k–10k/day | Live |
APILayerMarketplace of 40+ separate REST APIs (currency, geolocation, weather, market data) under one key. Developer Tools › API Directories | Freemium | API key | JSON | <100/day | Live |
APIs.guruMachine-readable directory of OpenAPI specs for thousands of public APIs. Developer Tools › API Directories | Free | None | JSON | Unlimited | Live |
APIzoneIndependent uptime probes and outage history for 294 popular APIs like Stripe, OpenAI and AWS. Developer Tools › Monitoring | Freemium | None | JSON | 1k–10k/day | Live |
AquanodeLive GPU rental prices and availability aggregated from nine cloud providers (RunPod, Akash, Vast.ai, etc). Developer Tools › Hosting | Free | None | JSON | Unlimited | Live |
ASORadarApp Store and Google Play reviews, sentiment, rankings, keyword tracking, and app metadata. Developer Tools › SEO | Freemium | API key | JSON | — | Live |
AutomStructured JSON search results (organic, knowledge graph) from Google, Bing, Brave and Perplexity. Developer Tools › Search & SERP | Freemium | API key | JSON | — | Live |
Bacon IpsumGenerates meat-themed lorem ipsum filler text as paragraphs or sentences, in JSON, XML or plain text. Developer Tools › Mock & Test APIs | Free | None | JSON | Unlimited | Live |
BaconMockupPlaceholder meat/bacon JPEG images at any width x height, for design mockups and prototypes. Developer Tools › Mock & Test APIs | None | Binary | Unlimited | Live | |
Brand.devFetches a company's logo, brand colors, fonts and metadata, or scrapes any URL as clean Markdown. Developer Tools › Web Scraping | Freemium | API key | JSON | — | Live |
Brave Search APILive web search index API returning ranked results, images, news, and AI-grounded answers. Developer Tools › Search & SERP | Freemium | API key | JSON | <100/day | Untested |
BrewPageFree, no-signup instant hosting for HTML, Markdown, JSON, KV data, and multi-file sites. Developer Tools › Hosting | Free | None | JSON | — | Untested |
BrowserCatManaged cloud Chromium reachable over CDP/Playwright/Puppeteer for scraping, screenshots, PDFs and tests. Developer Tools › Web Scraping | Freemium | API key | Binary | <100/day | Untested |
CDNJSSearch and inspect libraries hosted on the cdnjs CDN, including versions, files and SRI hashes. Developer Tools › Package Registries | None | JSON | Unlimited | Live | |
CodeforcesCompetitive programming data: user ratings, contest results, problems, and submissions. Developer Tools › Code Execution | None | JSON | — | Live | |
Compiler Explorer (godbolt.org)Compiles code in 80+ languages across thousands of compiler versions, returning assembly and run output. Developer Tools › Code Execution | Free | None | JSON | Unlimited | Live |
CorsfixProxies any HTTP request and adds CORS headers so browser JavaScript can call blocked third-party APIs. Developer Tools › Hosting | Freemium | None | JSON | — | Live |
crates.ioRust crate metadata, versions, downloads and dependencies from the official crates.io registry. Developer Tools › Package Registries | Free | None | JSON | Unlimited | Live |
Crawl ReadinessChecks if AI crawlers (GPTBot, ClaudeBot, PerplexityBot, etc.) can read a site; scores 0-100 with fixes. Developer Tools › SEO | Freemium | API key | JSON | <100/day | Live |
CrawlGraphLooks up which domains link to a given site, with authority scores, from Common Crawl snapshots. Developer Tools › SEO | Freemium | API key | JSON | <100/day | Live |
DigMyNameChecks domain availability and compares registrar prices across 50+ TLDs, no key required. Developer Tools › WHOIS & DNS | Free | None | JSON | 10k+/day | Live |
Docker Hub APILooks up public Docker image metadata—tags, digests, architectures—for any Docker Hub repository. Developer Tools › Package Registries | Freemium | API key | JSON | — | Live |
Domain IntelligenceWHOIS/RDAP, DNS, SSL certificate, subdomain and SPF/DMARC/DKIM data for a domain in one call. Developer Tools › WHOIS & DNS | Freemium | API key | JSON | <100/day | Live |
Domainr (Fastly)Domain name suggestions and registration status (available, parked, premium, for sale) across TLDs. Developer Tools › WHOIS & DNS | API key | JSON | — | Deprecated | |
DomScanDomain, DNS, WHOIS/RDAP, TLS, typosquatting and brand-monitoring lookups across 1,100+ TLDs. Developer Tools › WHOIS & DNS | Freemium | API key | JSON | — | Live |
Drupal.org APIRead-only REST API for Drupal.org's own projects, modules, releases, issues and users. Developer Tools › Package Registries | Free | None | JSON | — | Live |
DummyJSONFree placeholder REST API returning mock products, users, carts, posts and todos as JSON. Developer Tools › Mock & Test APIs | Free | None | JSON | Unlimited | Live |
English Random WordsRandom English words with definitions and pronunciations; also covers six other languages. Developer Tools › Mock & Test APIs | Free | None | JSON | — | Down |
EveryInfraPay-per-call scraping of 89+ social, review and shopping platforms, plus web search and CAPTCHA solving. Developer Tools › Web Scraping | Freemium | API key | JSON | — | Live |
ExaMeaning-based web search that returns page text, highlights and cited answers, sized for LLM context. Developer Tools › Search & SERP | Freemium | API key | JSON | <100/day | Live |
ExtendsClass JSON StorageStore and fetch small JSON blobs (bins) over a simple REST API, for tutorials or mocking. Developer Tools › Mock & Test APIs | Free | API key | JSON | 100–1k/day | Untested |
FakeStoreAPIFake but realistic e-commerce data (products, carts, users, login) for prototyping shopping apps. Developer Tools › Mock & Test APIs | Free | None | JSON | Unlimited | Live |
flakyMock REST API for testing error handling: force status codes, latency or failure rates via query params. Developer Tools › Mock & Test APIs | Freemium | None | JSON | 10k+/day | Live |
Format JSON Online Dummy APIFree canned REST endpoints (users, products, orders, analytics) for frontend testing. Developer Tools › Mock & Test APIs | Free | None | JSON | Unlimited | Live |
GeekflareWeb scraping, screenshots, PDF generation, DNS/TLS checks and search via one credit-based REST API. Developer Tools › Web Scraping | Freemium | API key | JSON | — | Live |
GeneradorDNI APIGenerates fake but checksum-valid Spanish DNI/NIE/CIF numbers, IBANs, profiles and vehicle data for testing. Developer Tools › Mock & Test APIs | Freemium | None | JSON | Unlimited | Live |
GitHub REST APIOfficial API for GitHub repositories, issues, pull requests, users, and organizations. Developer Tools › Package Registries | Free | API key | JSON | 10k+/day | Live |
GoRESTRealistic fake users, posts, comments and todos with full CRUD, reseeded daily, for testing and prototyping. Developer Tools › Mock & Test APIs | Free | API key | JSON | Unlimited | Live |
HackerEarth Code Evaluation APICompiles and runs submitted code in many languages asynchronously, with status/result lookup by submission id. Developer Tools › Code Execution | Freemium | API key | JSON | — | Untested |
HackerTarget IP Tools APIASN, DNS, reverse DNS/IP, WHOIS, GeoIP, HTTP header and subnet lookups for any IP or domain as plain text. Developer Tools › WHOIS & DNS | Freemium | None | CSV | <100/day | Live |
HasData: Structured Web Data APIsExtracts structured JSON from Google Search, Maps, Amazon, Zillow, and general web pages via 40 endpoints. Developer Tools › Web Scraping | Freemium | API key | JSON | — | Live |
HexRegistry API for Elixir/Erlang packages: versions, releases, owners, dependencies and docs links. Developer Tools › Package Registries | Freemium | None | JSON | Unlimited | Live |
HipsumGenerates hipster-themed lorem ipsum placeholder text, plain or mixed with Latin words. Developer Tools › Mock & Test APIs | Free | None | JSON | Unlimited | Live |
HOL Registry BrokerSearch and resolve AI agents, MCP servers, and protocols indexed across multiple public registries. Developer Tools › API Directories | Freemium | API key | JSON | — | Live |
Host.ioDNS records, backlinks, IP/ASN and related-domain data across 600M+ registered domains. Developer Tools › WHOIS & DNS | Freemium | API key | JSON | <100/day | Live |
HTTP CatReturns a cat image for any HTTP status code, useful for error pages and status demos. Developer Tools › Mock & Test APIs | Free | None | Binary | Unlimited | Live |
httpbinEchoes back HTTP requests for testing: headers, auth, redirects, status codes, delays, and more. Developer Tools › Mock & Test APIs | Free | None | JSON | Unlimited | Live |
import.ioBuilds custom extractors that turn any website into structured JSON, with scheduling and JS rendering. Developer Tools › Web Scraping | Free trial | API key | JSON | — | Untested |
IP2WHOIS Information LookupDomain WHOIS records—registrant, dates, nameservers—by domain name, returned as JSON or XML. Developer Tools › WHOIS & DNS | Freemium | API key | JSON | <100/day | Untested |
Is This Site Down?Checks whether any domain is up, its HTTP status, latency and TLS cert expiry, probed from Singapore. Developer Tools › Monitoring | Free | None | JSON | 10k+/day | Live |
ItsThisForThatGenerates random 'it's X for Y' startup-pitch name pairs as JSON, JSONP, or plain text. Developer Tools › Mock & Test APIs | None | JSON | Unlimited | Live | |
JDoodle Compiler APIRuns programs in 100+ languages on remote sandboxes and returns output, with stdin and WebSocket streaming. Developer Tools › Code Execution | Freemium | API key | JSON | <100/day | Untested |
Jina AIConverts any URL into clean LLM-ready Markdown; also offers web search, embeddings and reranking. Developer Tools › Web Scraping | Freemium | API key | JSON | — | Live |
jsDelivrPackage version and CDN download-stats data for npm, GitHub, and WordPress files served over jsDelivr. Developer Tools › Package Registries | Free | None | JSON | Unlimited | Live |
JsonFabricaGenerates synthetic, relational JSON test data from reusable templates with sequences and batch jobs. Developer Tools › Mock & Test APIs | Free trial | API key | JSON | — | Live |
JSONingReady-made fake REST endpoints (products, users, carts, coupons) for prototyping frontends without a backend. Developer Tools › Mock & Test APIs | Free | None | JSON | — | Live |
JSONPlaceholderFake posts, comments, albums, photos, todos and users with relations; POST/PUT/PATCH/DELETE are simulated Developer Tools › Mock & Test APIs | Free | None | JSON | Unlimited | Live |
Judge0 CESandboxed code execution and judging across 60+ languages, with compile/runtime status and resource limits. Developer Tools › Code Execution | Freemium | None | JSON | — | Live |
LabelixaRenders ZPL/EPL/TSPL/CPCL thermal labels and barcodes to PNG/PDF, validates ZPL syntax. Developer Tools › Mock & Test APIs | Freemium | API key | Binary | 1k–10k/day | Live |
Libraries.ioMetadata, dependents, releases and repo stats for open-source packages across 30+ managers. Developer Tools › Package Registries | Freemium | API key | JSON | 10k+/day | Live |
LinkPreviewFetches a page's title, description and preview image from any URL for link previews. Developer Tools › Web Scraping | Freemium | API key | JSON | 1k–10k/day | Live |
LinkupWeb search returning sources, sourced answers or typed JSON, plus page fetch and async research for AI agents. Developer Tools › Search & SERP | Freemium | API key | JSON | 100–1k/day | Live |
Litport Free ProxyLive list of public HTTP/SOCKS proxies with protocol, geolocation, anonymity level and uptime data. Developer Tools › Web Scraping | Free | None | JSON | Unlimited | Live |
Magento WatchRelease dates, end-of-life dates and system requirements for Magento, Adobe Commerce and Mage-OS. Developer Tools › Monitoring | Free | None | JSON | Unlimited | Live |
MockarooGenerates realistic fake/test data (names, addresses, etc.) as JSON, CSV, SQL or XML. Developer Tools › Mock & Test APIs | Freemium | API key | JSON | 100–1k/day | Live |
MySQL Visual EXPLAINTurns a MySQL EXPLAIN plan into an interactive, embeddable visual query plan diagram. Developer Tools › Mock & Test APIs | Free | None | JSON | — | Untested |
NetworkCalcREST utilities for IP subnet math, DNS/WHOIS/SPF lookups, TLS certificate checks, and encoding conversions. Developer Tools › WHOIS & DNS | Freemium | None | JSON | — | Live |
npm RegistryQuery metadata, versions, dependencies and full-text search for npm/Node.js packages. Developer Tools › Package Registries | None | JSON | Unlimited | Live | |
NuGet.NET/NuGet package search, versions, metadata and download URLs from nuget.org's V3 API. Developer Tools › Package Registries | Free | None | JSON | Unlimited | Live |
OlostepScrapes, crawls, and semantically searches any site, returning Markdown, HTML, JSON, or PDF. Developer Tools › Web Scraping | Freemium | API key | JSON | — | Untested |
Open Page RankDomain authority scores (0-10) with monthly history, derived from Common Crawl's web graph. Developer Tools › SEO | Freemium | API key | JSON | 1k–10k/day | Untested |
OpenSERP CloudLive search results from Google, Bing, and other engines through one normalized JSON API. Developer Tools › Search & SERP | Freemium | API key | JSON | — | Live |
OutageDeckAggregated real-time status and incident history for 180+ cloud and SaaS providers. Developer Tools › Monitoring | Freemium | None | JSON | 1k–10k/day | Live |
OYYI88+ endpoints for image editing, PDF manipulation, OCR and AI vision/document intelligence. Developer Tools › Mock & Test APIs | Freemium | API key | JSON | 100–1k/day | Untested |
PackagistPHP Composer package metadata, versions, download stats and security advisories. Developer Tools › Package Registries | Free | None | JSON | Unlimited | Live |
PHPHubChecks PHP code for syntax errors against a chosen PHP version and returns line-numbered results. Developer Tools › Mock & Test APIs | None | JSON | — | Untested | |
PlaceBearServes placeholder bear photos at any pixel size via a simple URL pattern, no key needed. Developer Tools › Mock & Test APIs | Free | None | Binary | Unlimited | Live |
PosthookSchedules webhook deliveries for a future time, with automatic retries and delivery tracking. Developer Tools › Monitoring | Freemium | API key | JSON | <100/day | Untested |
Postman EchoEchoes back request method, headers, body and query params; also test endpoints for auth, cookies and delays. Developer Tools › Mock & Test APIs | Free | None | JSON | Unlimited | Live |
Prismix Status APILive uptime and incident status for 75+ AI providers like OpenAI, Anthropic, and Cursor. Developer Tools › Monitoring | Free | None | JSON | Unlimited | Live |
ProxyCrawlCrawls and scrapes any URL you give it, returning HTML, Markdown or JSON, with JS rendering and proxies. Developer Tools › Web Scraping | Freemium | API key | JSON | — | Live |
ProxyScrape Free Proxy ListPublic HTTP, SOCKS4 and SOCKS5 proxies rechecked every minute, filterable by country, anonymity and timeout. Developer Tools › Web Scraping | Freemium | None | JSON | Unlimited | Live |
Random ProfilesGenerates fake user profiles and company records, 100+ fields each, with photos for seed/test data. Developer Tools › Mock & Test APIs | Free | API key | JSON | 100–1k/day | Live |
RandommerGenerates fake names, addresses, phone numbers, text, hashes and other mock data for testing. Developer Tools › Mock & Test APIs | Freemium | API key | JSON | 1k–10k/day | Live |
RandomUserGenerates randomized fake user profiles (name, address, photo, login) for testing apps. Developer Tools › Mock & Test APIs | Free | None | JSON | Unlimited | Live |
ReqResHosted mock REST API with fake user, order and post data for testing frontend code and QA automation. Developer Tools › Mock & Test APIs | Freemium | None | JSON | 100–1k/day | Live |
ReserpStructured Google search results (web, images, shopping, news, places) for scraping and SEO tools. Developer Tools › Search & SERP | Freemium | API key | JSON | 100–1k/day | Untested |
restful-api.devFake CRUD REST API with sample product data for testing and prototyping HTTP clients. Developer Tools › Mock & Test APIs | Freemium | None | JSON | <100/day | Live |
RoboHashTurns any text/hash into a deterministic robot, monster, cat, or avatar image for placeholder use. Developer Tools › Mock & Test APIs | Free | None | Binary | Unlimited | Live |
RubyGems.org APIRuby gem metadata: versions, dependencies, download counts, owners and search, from RubyGems.org. Developer Tools › Package Registries | Free | None | JSON | 10k+/day | Live |
SampuliGenerates synthetic, format-valid test data (people, IBANs, IDs, VINs) for 90 countries, no key needed. Developer Tools › Mock & Test APIs | Free | None | JSON | Unlimited | Live |
ScrapeNinjaHeadless-browser scraping API with Chrome TLS fingerprinting, JS rendering, and rotating proxies. Developer Tools › Web Scraping | Freemium | API key | JSON | — | Untested |
ScraperAPIFetches any URL's rendered HTML through rotating proxies, JS rendering and CAPTCHA handling. Developer Tools › Web Scraping | Free trial | API key | JSON | — | Live |
scrapestackFetches any URL through rotating proxies, with JavaScript rendering and CAPTCHA handling. Developer Tools › Web Scraping | Freemium | API key | JSON | <100/day | Live |
ScrapflyFetches and renders any webpage through rotating proxies with anti-bot bypass, returning HTML/JSON. Developer Tools › Web Scraping | Freemium | API key | JSON | — | Live |
ScrapingAntHeadless-Chrome scraping API with rotating proxies, returning any page as HTML, JSON or Markdown. Developer Tools › Web Scraping | Freemium | API key | JSON | 100–1k/day | Untested |
ScrapingDogFetches rendered HTML or pre-parsed JSON from any target site via rotating proxies and headless Chrome. Developer Tools › Web Scraping | Freemium | API key | JSON | — | Live |
SearchApiReal-time, structured search results (Google, Bing, Amazon and more) scraped and returned as JSON. Developer Tools › Search & SERP | Freemium | API key | JSON | — | Live |
SEO Score APIScores a URL's SEO, performance, accessibility, and AI-search readability across dozens of checks. Developer Tools › SEO | Freemium | API key | JSON | <100/day | Live |
SerpApiStructured JSON results scraped from Google, Bing, Amazon, YouTube, and other search/shopping engines. Developer Tools › Search & SERP | Freemium | API key | JSON | <100/day | Live |
SerperLive Google results as JSON: web, images, news, maps, places, shopping, Scholar and patents. Developer Tools › Search & SERP | Freemium | API key | JSON | — | Live |
SerplyStructured search results from Google, Bing, eBay and Reddit, sold as pay-as-you-go credits. Developer Tools › Search & SERP | Freemium | API key | JSON | <100/day | Live |
serpstackReal-time Google search results (organic listings, ads, local pack, knowledge graph) as structured JSON. Developer Tools › Search & SERP | Freemium | API key | JSON | <100/day | Untested |
Softwium SQL ValidatorChecks MySQL-style SQL query syntax and returns parser errors with line/column locations. Developer Tools › Mock & Test APIs | Free | None | JSON | Unlimited | Untested |
StaticallyFree CDN that serves any file from a GitHub, GitLab, Bitbucket, Gist or npm package by URL. Developer Tools › Hosting | Free | None | Binary | — | Live |
Status PizzaReturns a pizza-themed image or JSON for any HTTP status code, for demos and error pages. Developer Tools › Mock & Test APIs | None | Binary | Unlimited | Live | |
SuprsonicOne API key for 20+ agent capabilities: web search, scraping, TTS/STT, image gen, email/company lookup. Developer Tools › API Directories | Freemium | API key | JSON | — | Live |
SvixSends, retries, and logs outgoing webhooks for your app, with per-customer delivery portals. Developer Tools › Monitoring | Freemium | API key | JSON | 1k–10k/day | Live |
TalordataStructured search-engine results (Google, Bing, Yandex, DuckDuckGo) via a token-authenticated scraping API. Developer Tools › Search & SERP | Free trial | API key | JSON | — | Untested |
TavilyWeb search, page extraction, site crawl and cited research reports returned as clean text for LLM agents. Developer Tools › Search & SERP | Freemium | API key | JSON | <100/day | Live |
ThunderbitTurns any URL into clean Markdown or AI-extracted JSON fields, with batch jobs and webhooks. Developer Tools › Web Scraping | Freemium | API key | JSON | — | Live |
ToolForte150 utility endpoints: IBAN/VAT validation, cron parsing, regex testing, format conversion, Dutch test data. Developer Tools › Mock & Test APIs | Freemium | API key | JSON | <100/day | Untested |
TotalShiftLeft SandboxSandbox with mock REST, GraphQL and SOAP endpoints plus 17 auth schemes for practicing API tests. Developer Tools › Mock & Test APIs | Free | None | JSON | 10k+/day | Live |
UUID GeneratorGenerates v1, v3, v4, v5 and timestamp-first UUIDs, singly or in bulk, and decodes existing ones. Developer Tools › Mock & Test APIs | Free | None | JSON | 10k+/day | Live |
Waldrand AvatarGenerates a stable SVG, PNG or WebP avatar/identicon from any string, no key or account needed. Developer Tools › Mock & Test APIs | Free | None | Binary | 10k+/day | Live |
WebclawTurns any public URL into markdown/JSON, plus async site crawling, search-and-scrape, and LLM extraction. Developer Tools › Web Scraping | Freemium | API key | JSON | 100–1k/day | Untested |
WebScraping.AITurns any webpage into clean text, rendered HTML, or AI-structured JSON via managed proxies. Developer Tools › Web Scraping | Freemium | API key | JSON | — | Live |
What The CommitRandom, joke commit-message generator, also available as plain text or JSON with a permalink. Developer Tools › Mock & Test APIs | None | JSON | Unlimited | Live | |
WhoisXML API Domain AvailabilityChecks whether a domain is free to register, using a fast DNS check or a slower DNS-plus-WHOIS/RDAP check. Developer Tools › WHOIS & DNS | Free trial | API key | JSON | — | Live |
x402 ListDirectory of x402-protocol pay-per-call APIs with live pricing, uptime and on-chain settlement data. Developer Tools › API Directories | Freemium | None | JSON | — | Live |
Yes NoReturns a random yes, no, or rare maybe answer with a matching reaction GIF; supports forcing an answer. Developer Tools › Mock & Test APIs | Free | None | JSON | Unlimited | Live |
ZenRowsFetches any webpage past anti-bot defenses with JS rendering and proxies, returning HTML or JSON. Developer Tools › Web Scraping | Freemium | API key | JSON | — | Live |
AbacusFreeLive
Key/value counter service for tracking page hits or custom events with a single GET request, no key needed.
None · JSON
<100/day
no machine-readable spec
AddressMockFreeLive
Generates format-correct sample addresses (street, city, ZIP, phone) for 7 countries, for testing forms.
None · JSON
Unlimited
OpenAPI spec · llms.txt
Agent NexusFreemiumLive
Searchable registry of APIs, MCP servers, and CLIs that AI agents can call, with live health data.
API key · JSON
100–1k/day
OpenAPI spec · MCP server · llms.txt
AgentDealsFreeLive
Search and compare developer tool free tiers, startup credits, and recent pricing changes.
None · JSON
Unlimited
OpenAPI spec · llms.txt
Airport GapFreeLive
Airport records by IATA code, airport-to-airport distances and a favourites store for practising API tests.
None · JSON
10k+/day
no machine-readable spec
Amazon Scraper APIFreemiumLive
Structured JSON for Amazon product, search and review data across 20 marketplaces; pay per success.
API key · JSON
—
OpenAPI spec · llms.txt
AnyAPIFree trialLive
Pay-per-request gateway to hundreds of scraping and data APIs with automatic provider failover.
API key · JSON
—
OpenAPI spec · llms.txt
AnycrapFreeLive
35,000+ AI-generated absurdist product concepts with names, descriptions and images for mock data.
API key · JSON
—
no machine-readable spec
API LeagueFreemiumLive
Single-key hub bundling separate APIs for jokes, news, books, recipes, games and art search.
API key · JSON
<100/day
no machine-readable spec
API Status CheckFreemiumLive
Independent uptime and outage status for 190+ developer APIs like OpenAI, Stripe, AWS and GitHub.
None · JSON
1k–10k/day
llms.txt
APILayerFreemiumLive
Marketplace of 40+ separate REST APIs (currency, geolocation, weather, market data) under one key.
API key · JSON
<100/day
no machine-readable spec
APIs.guruFreeLive
Machine-readable directory of OpenAPI specs for thousands of public APIs.
None · JSON
Unlimited
OpenAPI spec
APIzoneFreemiumLive
Independent uptime probes and outage history for 294 popular APIs like Stripe, OpenAI and AWS.
None · JSON
1k–10k/day
OpenAPI spec · llms.txt
AquanodeFreeLive
Live GPU rental prices and availability aggregated from nine cloud providers (RunPod, Akash, Vast.ai, etc).
None · JSON
Unlimited
llms.txt
ASORadarFreemiumLive
App Store and Google Play reviews, sentiment, rankings, keyword tracking, and app metadata.
API key · JSON
—
OpenAPI spec · llms.txt
AutomFreemiumLive
Structured JSON search results (organic, knowledge graph) from Google, Bing, Brave and Perplexity.
API key · JSON
—
no machine-readable spec
Bacon IpsumFreeLive
Generates meat-themed lorem ipsum filler text as paragraphs or sentences, in JSON, XML or plain text.
None · JSON
Unlimited
no machine-readable spec
BaconMockupLive
Placeholder meat/bacon JPEG images at any width x height, for design mockups and prototypes.
None · Binary
Unlimited
no machine-readable spec
Brand.devFreemiumLive
Fetches a company's logo, brand colors, fonts and metadata, or scrapes any URL as clean Markdown.
API key · JSON
—
OpenAPI spec · llms.txt
Brave Search APIFreemiumUntested
Live web search index API returning ranked results, images, news, and AI-grounded answers.
API key · JSON
<100/day
no machine-readable spec
BrewPageFreeUntested
Free, no-signup instant hosting for HTML, Markdown, JSON, KV data, and multi-file sites.
None · JSON
—
OpenAPI spec · llms.txt
BrowserCatFreemiumUntested
Managed cloud Chromium reachable over CDP/Playwright/Puppeteer for scraping, screenshots, PDFs and tests.
API key · Binary
<100/day
llms.txt
CDNJSLive
Search and inspect libraries hosted on the cdnjs CDN, including versions, files and SRI hashes.
None · JSON
Unlimited
no machine-readable spec
CodeforcesLive
Competitive programming data: user ratings, contest results, problems, and submissions.
None · JSON
—
no machine-readable spec
Compiler Explorer (godbolt.org)FreeLive
Compiles code in 80+ languages across thousands of compiler versions, returning assembly and run output.
None · JSON
Unlimited
no machine-readable spec
CorsfixFreemiumLive
Proxies any HTTP request and adds CORS headers so browser JavaScript can call blocked third-party APIs.
None · JSON
—
no machine-readable spec
crates.ioFreeLive
Rust crate metadata, versions, downloads and dependencies from the official crates.io registry.
None · JSON
Unlimited
no machine-readable spec
Crawl ReadinessFreemiumLive
Checks if AI crawlers (GPTBot, ClaudeBot, PerplexityBot, etc.) can read a site; scores 0-100 with fixes.
API key · JSON
<100/day
llms.txt
CrawlGraphFreemiumLive
Looks up which domains link to a given site, with authority scores, from Common Crawl snapshots.
API key · JSON
<100/day
llms.txt
DigMyNameFreeLive
Checks domain availability and compares registrar prices across 50+ TLDs, no key required.
None · JSON
10k+/day
OpenAPI spec · llms.txt
Docker Hub APIFreemiumLive
Looks up public Docker image metadata—tags, digests, architectures—for any Docker Hub repository.
API key · JSON
—
OpenAPI spec · llms.txt
Domain IntelligenceFreemiumLive
WHOIS/RDAP, DNS, SSL certificate, subdomain and SPF/DMARC/DKIM data for a domain in one call.
API key · JSON
<100/day
no machine-readable spec
Domainr (Fastly)Deprecated
Domain name suggestions and registration status (available, parked, premium, for sale) across TLDs.
API key · JSON
—
no machine-readable spec
DomScanFreemiumLive
Domain, DNS, WHOIS/RDAP, TLS, typosquatting and brand-monitoring lookups across 1,100+ TLDs.
API key · JSON
—
OpenAPI spec · llms.txt
Drupal.org APIFreeLive
Read-only REST API for Drupal.org's own projects, modules, releases, issues and users.
None · JSON
—
no machine-readable spec
DummyJSONFreeLive
Free placeholder REST API returning mock products, users, carts, posts and todos as JSON.
None · JSON
Unlimited
no machine-readable spec
English Random WordsFreeDown
Random English words with definitions and pronunciations; also covers six other languages.
None · JSON
—
no machine-readable spec
EveryInfraFreemiumLive
Pay-per-call scraping of 89+ social, review and shopping platforms, plus web search and CAPTCHA solving.
API key · JSON
—
OpenAPI spec · llms.txt
ExaFreemiumLive
Meaning-based web search that returns page text, highlights and cited answers, sized for LLM context.
API key · JSON
<100/day
OpenAPI spec
ExtendsClass JSON StorageFreeUntested
Store and fetch small JSON blobs (bins) over a simple REST API, for tutorials or mocking.
API key · JSON
100–1k/day
OpenAPI spec
FakeStoreAPIFreeLive
Fake but realistic e-commerce data (products, carts, users, login) for prototyping shopping apps.
None · JSON
Unlimited
OpenAPI spec
flakyFreemiumLive
Mock REST API for testing error handling: force status codes, latency or failure rates via query params.
None · JSON
10k+/day
OpenAPI spec · llms.txt
Format JSON Online Dummy APIFreeLive
Free canned REST endpoints (users, products, orders, analytics) for frontend testing.
None · JSON
Unlimited
llms.txt
GeekflareFreemiumLive
Web scraping, screenshots, PDF generation, DNS/TLS checks and search via one credit-based REST API.
API key · JSON
—
OpenAPI spec · MCP server · llms.txt
GeneradorDNI APIFreemiumLive
Generates fake but checksum-valid Spanish DNI/NIE/CIF numbers, IBANs, profiles and vehicle data for testing.
None · JSON
Unlimited
no machine-readable spec
GitHub REST APIFreeLive
Official API for GitHub repositories, issues, pull requests, users, and organizations.
API key · JSON
10k+/day
OpenAPI spec
GoRESTFreeLive
Realistic fake users, posts, comments and todos with full CRUD, reseeded daily, for testing and prototyping.
API key · JSON
Unlimited
no machine-readable spec
HackerEarth Code Evaluation APIFreemiumUntested
Compiles and runs submitted code in many languages asynchronously, with status/result lookup by submission id.
API key · JSON
—
no machine-readable spec
HackerTarget IP Tools APIFreemiumLive
ASN, DNS, reverse DNS/IP, WHOIS, GeoIP, HTTP header and subnet lookups for any IP or domain as plain text.
None · CSV
<100/day
no machine-readable spec
HasData: Structured Web Data APIsFreemiumLive
Extracts structured JSON from Google Search, Maps, Amazon, Zillow, and general web pages via 40 endpoints.
API key · JSON
—
MCP server · llms.txt
HexFreemiumLive
Registry API for Elixir/Erlang packages: versions, releases, owners, dependencies and docs links.
None · JSON
Unlimited
no machine-readable spec
HipsumFreeLive
Generates hipster-themed lorem ipsum placeholder text, plain or mixed with Latin words.
None · JSON
Unlimited
no machine-readable spec
HOL Registry BrokerFreemiumLive
Search and resolve AI agents, MCP servers, and protocols indexed across multiple public registries.
API key · JSON
—
OpenAPI spec · llms.txt
Host.ioFreemiumLive
DNS records, backlinks, IP/ASN and related-domain data across 600M+ registered domains.
API key · JSON
<100/day
no machine-readable spec
HTTP CatFreeLive
Returns a cat image for any HTTP status code, useful for error pages and status demos.
None · Binary
Unlimited
no machine-readable spec
httpbinFreeLive
Echoes back HTTP requests for testing: headers, auth, redirects, status codes, delays, and more.
None · JSON
Unlimited
OpenAPI spec
import.ioFree trialUntested
Builds custom extractors that turn any website into structured JSON, with scheduling and JS rendering.
API key · JSON
—
OpenAPI spec
IP2WHOIS Information LookupFreemiumUntested
Domain WHOIS records—registrant, dates, nameservers—by domain name, returned as JSON or XML.
API key · JSON
<100/day
OpenAPI spec
Is This Site Down?FreeLive
Checks whether any domain is up, its HTTP status, latency and TLS cert expiry, probed from Singapore.
None · JSON
10k+/day
MCP server
ItsThisForThatLive
Generates random 'it's X for Y' startup-pitch name pairs as JSON, JSONP, or plain text.
None · JSON
Unlimited
no machine-readable spec
JDoodle Compiler APIFreemiumUntested
Runs programs in 100+ languages on remote sandboxes and returns output, with stdin and WebSocket streaming.
API key · JSON
<100/day
no machine-readable spec
Jina AIFreemiumLive
Converts any URL into clean LLM-ready Markdown; also offers web search, embeddings and reranking.
API key · JSON
—
no machine-readable spec
jsDelivrFreeLive
Package version and CDN download-stats data for npm, GitHub, and WordPress files served over jsDelivr.
None · JSON
Unlimited
no machine-readable spec
JsonFabricaFree trialLive
Generates synthetic, relational JSON test data from reusable templates with sequences and batch jobs.
API key · JSON
—
llms.txt
JSONingFreeLive
Ready-made fake REST endpoints (products, users, carts, coupons) for prototyping frontends without a backend.
None · JSON
—
no machine-readable spec
JSONPlaceholderFreeLive
Fake posts, comments, albums, photos, todos and users with relations; POST/PUT/PATCH/DELETE are simulated
None · JSON
Unlimited
no machine-readable spec
Judge0 CEFreemiumLive
Sandboxed code execution and judging across 60+ languages, with compile/runtime status and resource limits.
None · JSON
—
no machine-readable spec
LabelixaFreemiumLive
Renders ZPL/EPL/TSPL/CPCL thermal labels and barcodes to PNG/PDF, validates ZPL syntax.
API key · Binary
1k–10k/day
MCP server · llms.txt
Libraries.ioFreemiumLive
Metadata, dependents, releases and repo stats for open-source packages across 30+ managers.
API key · JSON
10k+/day
no machine-readable spec
LinkPreviewFreemiumLive
Fetches a page's title, description and preview image from any URL for link previews.
API key · JSON
1k–10k/day
no machine-readable spec
LinkupFreemiumLive
Web search returning sources, sourced answers or typed JSON, plus page fetch and async research for AI agents.
API key · JSON
100–1k/day
OpenAPI spec
Litport Free ProxyFreeLive
Live list of public HTTP/SOCKS proxies with protocol, geolocation, anonymity level and uptime data.
None · JSON
Unlimited
OpenAPI spec · llms.txt
Magento WatchFreeLive
Release dates, end-of-life dates and system requirements for Magento, Adobe Commerce and Mage-OS.
None · JSON
Unlimited
llms.txt
MockarooFreemiumLive
Generates realistic fake/test data (names, addresses, etc.) as JSON, CSV, SQL or XML.
API key · JSON
100–1k/day
no machine-readable spec
MySQL Visual EXPLAINFreeUntested
Turns a MySQL EXPLAIN plan into an interactive, embeddable visual query plan diagram.
None · JSON
—
OpenAPI spec
NetworkCalcFreemiumLive
REST utilities for IP subnet math, DNS/WHOIS/SPF lookups, TLS certificate checks, and encoding conversions.
None · JSON
—
llms.txt
npm RegistryLive
Query metadata, versions, dependencies and full-text search for npm/Node.js packages.
None · JSON
Unlimited
no machine-readable spec
NuGetFreeLive
.NET/NuGet package search, versions, metadata and download URLs from nuget.org's V3 API.
None · JSON
Unlimited
no machine-readable spec
OlostepFreemiumUntested
Scrapes, crawls, and semantically searches any site, returning Markdown, HTML, JSON, or PDF.
API key · JSON
—
llms.txt
Open Page RankFreemiumUntested
Domain authority scores (0-10) with monthly history, derived from Common Crawl's web graph.
API key · JSON
1k–10k/day
no machine-readable spec
OpenSERP CloudFreemiumLive
Live search results from Google, Bing, and other engines through one normalized JSON API.
API key · JSON
—
llms.txt
OutageDeckFreemiumLive
Aggregated real-time status and incident history for 180+ cloud and SaaS providers.
None · JSON
1k–10k/day
MCP server · llms.txt
OYYIFreemiumUntested
88+ endpoints for image editing, PDF manipulation, OCR and AI vision/document intelligence.
API key · JSON
100–1k/day
llms.txt
PackagistFreeLive
PHP Composer package metadata, versions, download stats and security advisories.
None · JSON
Unlimited
no machine-readable spec
PHPHubUntested
Checks PHP code for syntax errors against a chosen PHP version and returns line-numbered results.
None · JSON
—
no machine-readable spec
PlaceBearFreeLive
Serves placeholder bear photos at any pixel size via a simple URL pattern, no key needed.
None · Binary
Unlimited
no machine-readable spec
PosthookFreemiumUntested
Schedules webhook deliveries for a future time, with automatic retries and delivery tracking.
API key · JSON
<100/day
OpenAPI spec · llms.txt
Postman EchoFreeLive
Echoes back request method, headers, body and query params; also test endpoints for auth, cookies and delays.
None · JSON
Unlimited
llms.txt
Prismix Status APIFreeLive
Live uptime and incident status for 75+ AI providers like OpenAI, Anthropic, and Cursor.
None · JSON
Unlimited
llms.txt
ProxyCrawlFreemiumLive
Crawls and scrapes any URL you give it, returning HTML, Markdown or JSON, with JS rendering and proxies.
API key · JSON
—
llms.txt
ProxyScrape Free Proxy ListFreemiumLive
Public HTTP, SOCKS4 and SOCKS5 proxies rechecked every minute, filterable by country, anonymity and timeout.
None · JSON
Unlimited
OpenAPI spec
Random ProfilesFreeLive
Generates fake user profiles and company records, 100+ fields each, with photos for seed/test data.
API key · JSON
100–1k/day
OpenAPI spec · MCP server · llms.txt
RandommerFreemiumLive
Generates fake names, addresses, phone numbers, text, hashes and other mock data for testing.
API key · JSON
1k–10k/day
OpenAPI spec
RandomUserFreeLive
Generates randomized fake user profiles (name, address, photo, login) for testing apps.
None · JSON
Unlimited
no machine-readable spec
ReqResFreemiumLive
Hosted mock REST API with fake user, order and post data for testing frontend code and QA automation.
None · JSON
100–1k/day
llms.txt
ReserpFreemiumUntested
Structured Google search results (web, images, shopping, news, places) for scraping and SEO tools.
API key · JSON
100–1k/day
no machine-readable spec
restful-api.devFreemiumLive
Fake CRUD REST API with sample product data for testing and prototyping HTTP clients.
None · JSON
<100/day
no machine-readable spec
RoboHashFreeLive
Turns any text/hash into a deterministic robot, monster, cat, or avatar image for placeholder use.
None · Binary
Unlimited
no machine-readable spec
RubyGems.org APIFreeLive
Ruby gem metadata: versions, dependencies, download counts, owners and search, from RubyGems.org.
None · JSON
10k+/day
llms.txt
SampuliFreeLive
Generates synthetic, format-valid test data (people, IBANs, IDs, VINs) for 90 countries, no key needed.
None · JSON
Unlimited
llms.txt
ScrapeNinjaFreemiumUntested
Headless-browser scraping API with Chrome TLS fingerprinting, JS rendering, and rotating proxies.
API key · JSON
—
OpenAPI spec
ScraperAPIFree trialLive
Fetches any URL's rendered HTML through rotating proxies, JS rendering and CAPTCHA handling.
API key · JSON
—
llms.txt
scrapestackFreemiumLive
Fetches any URL through rotating proxies, with JavaScript rendering and CAPTCHA handling.
API key · JSON
<100/day
llms.txt
ScrapflyFreemiumLive
Fetches and renders any webpage through rotating proxies with anti-bot bypass, returning HTML/JSON.
API key · JSON
—
MCP server · llms.txt
ScrapingAntFreemiumUntested
Headless-Chrome scraping API with rotating proxies, returning any page as HTML, JSON or Markdown.
API key · JSON
100–1k/day
MCP server
ScrapingDogFreemiumLive
Fetches rendered HTML or pre-parsed JSON from any target site via rotating proxies and headless Chrome.
API key · JSON
—
llms.txt
SearchApiFreemiumLive
Real-time, structured search results (Google, Bing, Amazon and more) scraped and returned as JSON.
API key · JSON
—
MCP server
SEO Score APIFreemiumLive
Scores a URL's SEO, performance, accessibility, and AI-search readability across dozens of checks.
API key · JSON
<100/day
OpenAPI spec · llms.txt
SerpApiFreemiumLive
Structured JSON results scraped from Google, Bing, Amazon, YouTube, and other search/shopping engines.
API key · JSON
<100/day
llms.txt
SerperFreemiumLive
Live Google results as JSON: web, images, news, maps, places, shopping, Scholar and patents.
API key · JSON
—
no machine-readable spec
SerplyFreemiumLive
Structured search results from Google, Bing, eBay and Reddit, sold as pay-as-you-go credits.
API key · JSON
<100/day
llms.txt
serpstackFreemiumUntested
Real-time Google search results (organic listings, ads, local pack, knowledge graph) as structured JSON.
API key · JSON
<100/day
llms.txt
Softwium SQL ValidatorFreeUntested
Checks MySQL-style SQL query syntax and returns parser errors with line/column locations.
None · JSON
Unlimited
no machine-readable spec
StaticallyFreeLive
Free CDN that serves any file from a GitHub, GitLab, Bitbucket, Gist or npm package by URL.
None · Binary
—
no machine-readable spec
Status PizzaLive
Returns a pizza-themed image or JSON for any HTTP status code, for demos and error pages.
None · Binary
Unlimited
no machine-readable spec
SuprsonicFreemiumLive
One API key for 20+ agent capabilities: web search, scraping, TTS/STT, image gen, email/company lookup.
API key · JSON
—
OpenAPI spec · llms.txt
SvixFreemiumLive
Sends, retries, and logs outgoing webhooks for your app, with per-customer delivery portals.
API key · JSON
1k–10k/day
OpenAPI spec · llms.txt
TalordataFree trialUntested
Structured search-engine results (Google, Bing, Yandex, DuckDuckGo) via a token-authenticated scraping API.
API key · JSON
—
llms.txt
TavilyFreemiumLive
Web search, page extraction, site crawl and cited research reports returned as clean text for LLM agents.
API key · JSON
<100/day
no machine-readable spec
ThunderbitFreemiumLive
Turns any URL into clean Markdown or AI-extracted JSON fields, with batch jobs and webhooks.
API key · JSON
—
llms.txt
ToolForteFreemiumUntested
150 utility endpoints: IBAN/VAT validation, cron parsing, regex testing, format conversion, Dutch test data.
API key · JSON
<100/day
OpenAPI spec · llms.txt
TotalShiftLeft SandboxFreeLive
Sandbox with mock REST, GraphQL and SOAP endpoints plus 17 auth schemes for practicing API tests.
None · JSON
10k+/day
OpenAPI spec · llms.txt
UUID GeneratorFreeLive
Generates v1, v3, v4, v5 and timestamp-first UUIDs, singly or in bulk, and decodes existing ones.
None · JSON
10k+/day
no machine-readable spec
Waldrand AvatarFreeLive
Generates a stable SVG, PNG or WebP avatar/identicon from any string, no key or account needed.
None · Binary
10k+/day
no machine-readable spec
WebclawFreemiumUntested
Turns any public URL into markdown/JSON, plus async site crawling, search-and-scrape, and LLM extraction.
API key · JSON
100–1k/day
OpenAPI spec · llms.txt
WebScraping.AIFreemiumLive
Turns any webpage into clean text, rendered HTML, or AI-structured JSON via managed proxies.
API key · JSON
—
OpenAPI spec
What The CommitLive
Random, joke commit-message generator, also available as plain text or JSON with a permalink.
None · JSON
Unlimited
no machine-readable spec
WhoisXML API Domain AvailabilityFree trialLive
Checks whether a domain is free to register, using a fast DNS check or a slower DNS-plus-WHOIS/RDAP check.
API key · JSON
—
no machine-readable spec
x402 ListFreemiumLive
Directory of x402-protocol pay-per-call APIs with live pricing, uptime and on-chain settlement data.
None · JSON
—
OpenAPI spec · MCP server · llms.txt
Yes NoFreeLive
Returns a random yes, no, or rare maybe answer with a matching reaction GIF; supports forcing an answer.
None · JSON
Unlimited
no machine-readable spec
ZenRowsFreemiumLive
Fetches any webpage past anti-bot defenses with JS rendering and proxies, returning HTML or JSON.
API key · JSON
—
llms.txt
Nothing matches that combination. Clear the filters and start from the category.
Choosing a Developer Tools API
Is there a free Developer Tools API?
Yes. GitHub REST API, JSONPlaceholder, Abacus, AddressMock, AgentDeals and 40 others are free to use, and SerpApi, Agent Nexus, Amazon Scraper API, API League, API Status Check and 65 others have a free tier alongside paid plans.
Which Developer Tools APIs work without an API key?
JSONPlaceholder, Abacus, AddressMock, AgentDeals, Airport Gap and 57 others need no key or sign-up, so you can try them with a plain request.
Can I call a Developer Tools API from front-end JavaScript?
JSONPlaceholder, Abacus, AddressMock, AgentDeals, Airport Gap and 44 others allow cross-origin requests and need no key, so they work straight from the browser. For the others, call them from your server so your key stays private.
Can I use Developer Tools APIs in a commercial project?
GitHub REST API, AddressMock, Amazon Scraper API, AnyAPI, APILayer and 36 others permit commercial use. API League, LinkPreview, Linkup, OutageDeck and ReqRes restrict it, for example to non-commercial or attributed use, so read the terms first.
Which Developer Tools APIs work with AI agents?
Agent Nexus, Geekflare, Random Profiles and x402 List have both an MCP server and an OpenAPI spec. HasData: Structured Web Data APIs, Is This Site Down?, Labelixa, OutageDeck, Scrapfly and 2 others have an MCP server, so an AI agent can call them directly. GitHub REST API, AddressMock, AgentDeals, Amazon Scraper API, AnyAPI and 31 others publish an OpenAPI spec for generating clients and tools.
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