Machine Learning & AI APIs
Free machine learning and AI APIs: text generation, sentiment analysis, image recognition, speech to text, translation and embeddings, including open-source hosted models.
8 tested APIs with full docs · 8 need no key · 50 more listed
Tested, with full documentation
We called each of these before publishing. Every page carries a working curl command, the real JSON response it returned, parameters and common errors.
AI Economics Tools
Free AI cost calculator API with no key: token spend, context window sizing and agent-hour economics, each returning the result, the formula and a plain-English reading. Tested example included.
DreamThreads
Free dream analysis API with no key: POST a dream narrative and get back structured entities, actions, actors, locations and emotions with confidence scores. Tested example included.
Hugging Face Hub
Free model hub API with no key: search over a million models by task, library or tag, with download counts, likes and a trending score. Tested example included.
models.dev
Free AI model dataset with no key: one JSON document covering providers, models, pricing, context limits and capability flags, community-maintained on GitHub. Tested example included.
OpenRouter Models
Free LLM catalogue API with no key: every model OpenRouter routes to, with per-token pricing, context length, modalities and supported parameters. Tested example included.
Pollinations Text
Free text generation API with no key: put a prompt in the URL path and get generated plain text straight back. No JSON envelope, no account. Tested example included.
Statlyte
Free LLM pricing API with no key: per-model input, output, cache and batch rates, context windows, status and scheduled price changes. Tested example included.
TensorFeed
Free AI model API with no key: models grouped by provider with pricing, context windows, capability tags and a composite intelligence score with coverage metadata. Tested example included.
Choosing between these Machine Learning & AI APIs
AI and machine learning APIs are the fastest-moving category here, and the one where free tiers change most often. Almost all require an API key, and most cap free usage by tokens or requests per month rather than offering an unlimited tier.
Watch the terms rather than just the price: many providers train on submitted data by default on free tiers, which matters if you are sending anything sensitive or proprietary.
More Machine Learning & AI APIs in the directory
50 further APIs in this category, of which 5 need no API key. These are catalogued from the public-API lists and link straight to each provider's own documentation — we have not tested them yet, so treat the auth and CORS flags as the upstream list's claim rather than ours. They are promoted to a full tested page as we work through them.
| API | What it does | Auth |
|---|---|---|
| 1ClickImpact (AI Energy) | Track and offset the energy and carbon footprint of your AI/LLM usage via a simple API | KeyCORS |
| Advanced Multilanguage AI Translator (RapidAPI) | AI-powered translator supporting multiple languages with fast, context-aware responses | KeyCORS |
| AI For Thai | Free Various Thai AI API | KeyCORS |
| AI Learning Engine | Create, auto-grade, and analyze learning tasks with AI-based evaluations | KeyCORS |
| AI/ML | Access 100+ curated AI Models over 1 API | KeyCORS |
| BRAINIALL | PT-BR and Spanish audio transcription with diarization and SRT/VTT | KeyCORS |
| Chatwith | Build custom ChatGPT-style AI chatbots trained on your website and files, integrated with 5000+ apps — no coding, live in minutes. | KeyCORS |
| Clarifai | Computer Vision | OAuth |
| Cloudmersive | Image captioning, face recognition, NSFW classification | KeyCORS |
| cogDepot | Marketplace API for AI agents to post service listings, negotiate terms, and finalize deals, with an A2A Agent Card and JSON-RPC endpoint | Key |
| Cohere | Harness the power of language understanding. Join the developers and businesses who are using Cohere to generate, categorize and organize text at a scale that was previously unimaginable. | KeyCORS |
| CustomGPT.ai | RAG API with RESTful endpoints, comprehensive SDKs, and enterprise-grade reliability. | KeyCORS |
| DeepAI | Provides AI-powered APIs for text generation, image processing, and more | KeyCORS |
| Deepcode | AI for code review | None |
| Dialogflow | Natural Language Processing | Key |
| Eden | Get all AI models in one place, e.g. OpenAI, Google and lots more! | KeyCORS |
| EXUDE-API | Used for the primary ways for filtering the stopping, stemming words from the text data | NoneCORS |
| Face-api.js | JavaScript API for face detection, recognition, and emotion analysis using TensorFlow.js | None |
| Gandr | Text to speech API for voice agents. One voice in 23 languages, every render watermarked | KeyCORS |
| Gladia | Artificial intelligence API's | Key |
| GoldBean | OCR, Translation, NLP & ERNIE LLM via Baidu AI (free tier available) | Key |
| Google Gemini | Multimodal generative AI for text, vision, and code generation | Key |
| Groq | Fast AI inference API with free tier, supports Llama, Mixtral, Gemma models | KeyCORS |
| HarnessRouter | Run coding agent harnesses (Codex, Claude Code, Hermes) behind your product through one API | Key |
| Hirak FaceAPI | Face detection, face recognition with age estimation/gender estimation, accurate, no quota limits | Key |
| HOL Registry Broker | Discovery API for AI agents & MCP servers (search, verify, UAID, chat) | KeyCORS |
| Hugging Face | AI model hub with inference API for NLP, computer vision, and audio | KeyCORS |
| Imagga | Image Recognition Solutions like Tagging, Visual Search, NSFW moderation | Key |
| Inferdo | Computer Vision services like Facial detection, Image labeling, NSFW classification | Key |
| IPS Online | Face and License Plate Anonymization | Key |
| Irisnet | Realtime content moderation API that blocks or blurs unwanted images in real-time | KeyCORS |
| Jina AI | Free AI API for embeddings, reranking, and text processing | KeyCORS |
| Keen IO | Data Analytics | Key |
| Machinetutors | AI Solutions: Video/Image Classification & Tagging, NSFW, Icon/Image/Audio Search, NLP | KeyCORS |
| MediaCraft AI | Chinese content compliance review (17 platforms), EN↔CN translation, and SEO optimization. Pay-per-call via x402 (Solana USDC). | KeyCORS |
| MessengerX.io | A FREE API for developers to build and monetize personalized ML based chat apps | KeyCORS |
| NLP Cloud | NLP API using spaCy and transformers for NER, sentiments, classification, summarization, and more | Key |
| Not Human Search | AI tool discovery with agentic scoring for 8,600+ tools and MCP servers | NoneCORS |
| OpenAI | Use AI models such as ChatGPT or DALL-E to experience the capabilities of AI | KeyCORS |
| OpenVisionAPI | Open source computer vision API based on open source models | NoneCORS |
| Perspective | NLP API to return probability that if text is toxic, obscene, insulting or threatening | Key |
| Roboflow Universe | Pre-trained computer vision models | KeyCORS |
| SkyBiometry | Face Detection, Face Recognition and Face Grouping | Key |
| Spam Hunter | Free service to classify text as spam using ML | KeyCORS |
| Summarize Text with AI | This API generates customizable summaries of text and web pages using AI | KeyCORS |
| Time Door | A time series analysis API | KeyCORS |
| TranscriptFetch | YouTube transcript API for developers. Fetch captions from any video in production—no proxies, no IP blocks. Built for LLM, RAG, and MCP pipelines | KeyCORS |
| UnoRouter | OpenAI-compatible gateway routing chat/completions across 500+ models with a free tier | KeyCORS |
| Unplugg | Forecasting API for timeseries data | Key |
| WolframAlpha | Provides specific answers to questions using data and algorithms | Key |