OpenRouter

Unified API for 300+ LLMs from OpenAI, Anthropic, Meta, Mistral and more, with a free tier

Official docs outline

Extra Credit builds an outline of OpenRouter's docs the first time your work uses it. Until then, start at the official documentation.

MessengerX.io A FREE API for developers to build and monetize personalized ML based chat apps
Modelfax LLM pricing, context windows and deprecation dates, schema-validated and updated daily
NLP Cloud NLP API using spaCy and transformers for NER, sentiments, classification, summarization, and more
Nonobench Open-source benchmark of how well LLMs solve nonogram puzzles
Not Human Search AI tool discovery with agentic scoring for 8,600+ tools and MCP servers
onomeo OpenAI-compatible, about 30 free LLMs, 30 calls per 5 hours, optional pay-as-you-go, public beta
OpenVisionAPI Open source computer vision API based on open source models
Perspective NLP API to return probability that if text is toxic, obscene, insulting or threatening
QuelLLM Open-weight language model catalogue with memory requirements and installation metadata
Requesty OpenAI compatible LLM router for 600+ models, with a free tier for free models
Roboflow Universe Pre-trained computer vision models
SafeReel NSFW detection for images and full-length videos by URL, free tier