Sentiment Analysis APIs
Sentiment analysis here ranges from general to domain-specific. Google Cloud Natural Language and Cloudmersive score sentiment as part of wider NLP suites that also extract entities and analyze syntax, while FinSignals is built for markets, classifying Reddit and news posts about stocks as bullish or bearish with quality signals. All three run freemium plans. Free AI APIs →
| API | Pricing | Auth | Format | Free tier | Status |
|---|---|---|---|---|---|
Cloudmersive Natural Language ProcessingSentiment, entity extraction, POS tagging, language detection and translation via one text API. AI & Machine Learning › Text Analysis | Freemium | API key | JSON | <100/day | Untested |
FinSignalsClassifies Reddit and news posts about stocks into sentiment, bullish/bearish stance, and quality signals. AI & Machine Learning › Text Analysis | Freemium | API key | JSON | <100/day | Live |
Google Cloud Natural Language APISentiment, entity, syntax and content-classification analysis for text via Google Cloud. AI & Machine Learning › Text Analysis | Freemium | OAuth | JSON | 100–1k/day | Live |
Cloudmersive Natural Language ProcessingFreemiumUntested
Sentiment, entity extraction, POS tagging, language detection and translation via one text API.
API key · JSON
<100/day
OpenAPI spec
FinSignalsFreemiumLive
Classifies Reddit and news posts about stocks into sentiment, bullish/bearish stance, and quality signals.
API key · JSON
<100/day
no machine-readable spec
Google Cloud Natural Language APIFreemiumLive
Sentiment, entity, syntax and content-classification analysis for text via Google Cloud.
OAuth · JSON
100–1k/day
OpenAPI spec
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Choosing a Sentiment Analysis API
Is there a free Sentiment Analysis API?
Yes. Google Cloud Natural Language API, Cloudmersive Natural Language Processing and FinSignals have a free tier alongside paid plans. See all free AI APIs.
Which Sentiment Analysis APIs work without an API key?
All of them need a key or account. Cloudmersive Natural Language Processing and FinSignals give one out free when you sign up.
Can I use Sentiment Analysis APIs in a commercial project?
Google Cloud Natural Language API, Cloudmersive Natural Language Processing and FinSignals permit commercial use.
Which Sentiment Analysis APIs work with AI agents?
Google Cloud Natural Language API and Cloudmersive Natural Language Processing publish an OpenAPI spec for generating clients and tools.
Broader: Text Analysis APIs · AI & Machine Learning APIs