Last updated: July 2026. Looking for a free AI API to build into your app, automate tasks, or experiment with LLMs? Every major AI provider offers free API access — but the terms, limits, and model quality vary enormously. This guide compares every significant free AI API tier so you can pick the right one.
Quick Comparison Table
| Provider | Free API Offer | Rate Limit | Card Required? | API Type | Best For |
|---|---|---|---|---|---|
| Google AI Studio | ~1,500 req/day Gemini 2.5 Flash | 1,500 RPM | No | REST | Content, vision, reasoning |
| OpenRouter | 25+ free models | 20 RPM / 50 RPD | No | OpenAI-compatible | Multi-model apps |
| DeepSeek | 5M tokens one-time | 50 RPM | No | OpenAI-compatible | Coding, reasoning |
| Groq | Free LPU inference | 30 RPM | No | OpenAI-compatible | Real-time, speed-critical |
| Mistral AI | Free API tier | ~5 RPM | No | REST | EU privacy, multilingual |
| Cloudflare Workers AI | 10,000 Neurons/day | Dozens of models | No | REST | Edge, serverless |
| NVIDIA NIM | 1,000 free credits | Limited | Yes | REST | GPU inference |
| Cohere | 1,000 req/month | 5 RPM | No | REST | RAG, embeddings |
Which Free API Should You Use?
Three providers stand out for most use cases:
- Best overall free API: Google AI Studio. 1,500 requests/day to Gemini 2.5 Flash is unmatched. No card needed.
- Best for multi-model apps: OpenRouter. 25+ free models behind a single, OpenAI-compatible API.
- Best for speed: Groq. LPU-powered inference is the fastest free option by a wide margin.
For a full comparison of free models (not just APIs), see our Best Free AI Models guide.
Related: Free AI Tools Hub · Best Free AI Models 2026 · AI Model Comparison 2026