Address & Postal Code APIs
Two kinds of service live here: postal-code lookups and address verification. Keyless lookups cover specific countries, such as Postcodes.io for UK postcodes, ViaCEP for Brazilian CEPs and Sepomex for Mexico, while Zippopotam.us spans many countries for free. For US mail, Smarty checks street addresses against USPS data on a free trial, and Lob.com verifies and standardizes mailing addresses on paid plans.
| API | Pricing | Auth | Format | Free tier | Status |
|---|---|---|---|---|---|
Lob.comVerifies, autocompletes and standardizes US mailing addresses, plus ZIP and reverse-geocode lookups. Location & Mapping › Address & Postal Code | Paid | API key | JSON | — | Live |
Metadapi Zip CodeUS ZIP code lookup with demographics, IRS income stats, distance and radius search, updated monthly. Location & Mapping › Address & Postal Code | Freemium | API key | JSON | 100–1k/day | Live |
OpenPLZ APIStreet, postal code, and municipality lookups for Germany, Austria, Switzerland, Liechtenstein. Location & Mapping › Address & Postal Code | None | JSON | Unlimited | Live | |
PontoFatoBrazilian postal code (CEP) lookups with coordinates, addresses and companies registered there. Location & Mapping › Address & Postal Code | Freemium | None | JSON | Unlimited | Live |
PostaliPostal code lookup, validation, and search for Mexico, Colombia, and Spain from official postal data. Location & Mapping › Address & Postal Code | Free | None | JSON | Unlimited | Live |
Postcodes.ioValidates and geocodes UK postcodes, returning administrative, electoral and census-area data. Location & Mapping › Address & Postal Code | None | JSON | Unlimited | Live | |
RevAddressUS address standardization, parsing, and geocoding on Census data, with BYOK USPS verification. Location & Mapping › Address & Postal Code | Freemium | API key | JSON | <100/day | Down |
SepomexLooks up Mexican zip codes, states, municipalities and cities from the SEPOMEX postal dataset. Location & Mapping › Address & Postal Code | Free | None | JSON | 10k+/day | Live |
Smarty US Autocomplete ProAutocompletes and validates US street addresses against USPS data as users type. Location & Mapping › Address & Postal Code | Free trial | API key | JSON | <100/day | Live |
Smarty US Extract APIFinds and standardizes US postal addresses embedded in free-form text, like emails or documents. Location & Mapping › Address & Postal Code | Free trial | API key | JSON | — | Untested |
TrustyDataFrench address verification, geocoding, SIRENE company search and trade-area analysis from open data. Location & Mapping › Address & Postal Code | Freemium | API key | JSON | 1k–10k/day | Live |
US Street AddressValidates and standardizes US street addresses against USPS and proprietary datasets. Location & Mapping › Address & Postal Code | Free trial | API key | JSON | — | Live |
US ZipCodeLooks up US ZIP Codes from city/state, or city/state from a ZIP Code, via USPS-based data. Location & Mapping › Address & Postal Code | Free trial | API key | JSON | — | Live |
ViaCEPLooks up Brazilian street addresses and IBGE/DDD codes by postal code (CEP), no key needed. Location & Mapping › Address & Postal Code | Free | None | JSON | Unlimited | Live |
ZipCodeAPIDistance, radius search, and location lookups between US zip codes and Canadian postal codes. Location & Mapping › Address & Postal Code | Freemium | API key | JSON | 100–1k/day | Live |
ZipcodestackLooks up postal codes worldwide with location, distance, radius and geometry queries. Location & Mapping › Address & Postal Code | Freemium | API key | JSON | <100/day | Live |
Zippopotam.usLooks up place, state and coordinates for a postal code, or postal codes for a city, across 60+ countries. Location & Mapping › Address & Postal Code | Free | None | JSON | Unlimited | Live |
ZiptasticLooks up country, state, and city for a US ZIP code with a single GET request. Location & Mapping › Address & Postal Code | Free | None | JSON | Unlimited | Live |
Lob.comPaidLive
Verifies, autocompletes and standardizes US mailing addresses, plus ZIP and reverse-geocode lookups.
API key · JSON
—
no machine-readable spec
Metadapi Zip CodeFreemiumLive
US ZIP code lookup with demographics, IRS income stats, distance and radius search, updated monthly.
API key · JSON
100–1k/day
no machine-readable spec
OpenPLZ APILive
Street, postal code, and municipality lookups for Germany, Austria, Switzerland, Liechtenstein.
None · JSON
Unlimited
no machine-readable spec
PontoFatoFreemiumLive
Brazilian postal code (CEP) lookups with coordinates, addresses and companies registered there.
None · JSON
Unlimited
MCP server · llms.txt
PostaliFreeLive
Postal code lookup, validation, and search for Mexico, Colombia, and Spain from official postal data.
None · JSON
Unlimited
no machine-readable spec
Postcodes.ioLive
Validates and geocodes UK postcodes, returning administrative, electoral and census-area data.
None · JSON
Unlimited
no machine-readable spec
RevAddressFreemiumDown
US address standardization, parsing, and geocoding on Census data, with BYOK USPS verification.
API key · JSON
<100/day
OpenAPI spec · llms.txt
SepomexFreeLive
Looks up Mexican zip codes, states, municipalities and cities from the SEPOMEX postal dataset.
None · JSON
10k+/day
no machine-readable spec
Smarty US Autocomplete ProFree trialLive
Autocompletes and validates US street addresses against USPS data as users type.
API key · JSON
<100/day
no machine-readable spec
Smarty US Extract APIFree trialUntested
Finds and standardizes US postal addresses embedded in free-form text, like emails or documents.
API key · JSON
—
no machine-readable spec
TrustyDataFreemiumLive
French address verification, geocoding, SIRENE company search and trade-area analysis from open data.
API key · JSON
1k–10k/day
llms.txt
US Street AddressFree trialLive
Validates and standardizes US street addresses against USPS and proprietary datasets.
API key · JSON
—
no machine-readable spec
US ZipCodeFree trialLive
Looks up US ZIP Codes from city/state, or city/state from a ZIP Code, via USPS-based data.
API key · JSON
—
no machine-readable spec
ViaCEPFreeLive
Looks up Brazilian street addresses and IBGE/DDD codes by postal code (CEP), no key needed.
None · JSON
Unlimited
no machine-readable spec
ZipCodeAPIFreemiumLive
Distance, radius search, and location lookups between US zip codes and Canadian postal codes.
API key · JSON
100–1k/day
OpenAPI spec
ZipcodestackFreemiumLive
Looks up postal codes worldwide with location, distance, radius and geometry queries.
API key · JSON
<100/day
OpenAPI spec · llms.txt
Zippopotam.usFreeLive
Looks up place, state and coordinates for a postal code, or postal codes for a city, across 60+ countries.
None · JSON
Unlimited
no machine-readable spec
ZiptasticFreeLive
Looks up country, state, and city for a US ZIP code with a single GET request.
None · JSON
Unlimited
no machine-readable spec
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Choosing an Address & Postal Code API
Is there a free Address & Postal Code API?
Yes. Zippopotam.us, Postali, Sepomex, ViaCEP and Ziptastic are free to use, and Metadapi Zip Code, PontoFato, TrustyData, ZipCodeAPI and Zipcodestack have a free tier alongside paid plans.
Which Address & Postal Code APIs work without an API key?
Zippopotam.us, Postcodes.io, OpenPLZ API, PontoFato, Postali and 3 others need no key or sign-up, so you can try them with a plain request.
Can I call an Address & Postal Code API from front-end JavaScript?
Zippopotam.us, Postcodes.io, OpenPLZ API, Postali, Sepomex and 2 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 Address & Postal Code APIs in a commercial project?
US Street Address, Metadapi Zip Code, Sepomex, Smarty US Autocomplete Pro, US ZipCode and 1 other permit commercial use. Postcodes.io and Zipcodestack restrict it, for example to non-commercial or attributed use, so read the terms first.
Which Address & Postal Code APIs work with AI agents?
PontoFato has an MCP server, so an AI agent can call it directly. ZipCodeAPI and Zipcodestack publish an OpenAPI spec for generating clients and tools.
More specific: Address Validation APIs · ZIP Code Lookup APIs
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