Machine learning APIs provide pre-trained models and ML infrastructure for predictions, classifications, and data analysis. Add intelligent features to your apps without deep ML expertise.
Last verified: April 1, 2026
| Name | Description | Auth | HTTPS | CORS | Status |
|---|---|---|---|---|---|
| AI For Thai | Free Various Thai AI API | apikey | Yes | yes | alive |
| Clarifai | Computer Vision | oauth | Yes | unknown | alive |
| Cloudmersive | Image captioning, face recognition, NSFW classification | apikey | Yes | yes | alive |
| Dialogflow | Natural Language Processing | apikey | Yes | unknown | alive |
| EXUDE-API | Used for the primary ways for filtering the stopping, stemming words from the text data | none | Yes | yes | alive |
| Hirak FaceAPI | Face detection, face recognition with age estimation/gender estimation, accurate, no quota limits | apikey | Yes | unknown | alive |
| Inferdo | Computer Vision services like Facial detection, Image labeling, NSFW classification | apikey | Yes | unknown | alive |
| IPS Online | Face and License Plate Anonymization | apikey | Yes | unknown | dead |
| Irisnet | Realtime content moderation API that blocks or blurs unwanted images in real-time | apikey | Yes | yes | alive |
| Machinetutors | AI Solutions: Video/Image Classification & Tagging, NSFW, Icon/Image/Audio Search, NLP | apikey | Yes | yes | dead |
| MessengerX.io | A FREE API for developers to build and monetize personalized ML based chat apps | apikey | Yes | yes | alive |
| NLP Cloud | NLP API using spaCy and transformers for NER, sentiments, classification, summarization, and more | apikey | Yes | unknown | alive |
| OpenVisionAPI | Open source computer vision API based on open source models | none | Yes | yes | dead |
| Perspective | NLP API to return probability that if text is toxic, obscene, insulting or threatening | apikey | Yes | unknown | alive |
| SkyBiometry | Face Detection, Face Recognition and Face Grouping | apikey | Yes | unknown | alive |
| Time Door | A time series analysis API | apikey | Yes | yes | alive |
| Unplugg | Forecasting API for timeseries data | apikey | Yes | unknown | alive |
| WolframAlpha | Provides specific answers to questions using data and algorithms | apikey | Yes | unknown | dead |
2 of these APIs require no authentication — you can start making requests immediately without signing up for an account. Just pick one from the table above, check its documentation, and send your first request.
15 APIs in this category require a free API key. This usually means creating a free account on the provider's website and copying your key from the dashboard. The process typically takes less than a minute.
Not sure where to start? Look for APIs marked as "alive" in the status column — these were recently verified as working. For browser-based projects, check that the API supports CORS.
Yes, all APIs listed on API Bouncer have a free tier. Some are completely open (no sign-up needed), while others require a free account to get an API key. Free tiers typically have rate limits — check each API's documentation for specifics.
It depends on your needs. Consider: Do you need authentication or prefer no-auth? Does your project need CORS support for browser access? How many requests will you make? Start with a no-auth API to prototype quickly, then switch to a more feature-rich option if needed.
We run periodic health checks on all listed APIs. The "Status" column shows whether each API was responding at our last check. APIs marked as "alive" were recently verified. You can also test any API yourself using curl or our guides on testing APIs.
Most free APIs allow commercial use, but terms vary by provider. Always check the specific API's terms of service. Some APIs have separate free and commercial tiers with different rate limits.
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