Most AI APIs require a credit card before you write a single line of code. Here are the platforms that give you a free API key to start building immediately.
Credit-based pay-per-use with token-settled billing. No monthly subscription. Paid credits never expire.
Replace multiple AI subscriptions with one wallet that includes routing, failover, and optimization.
Sign up, get an API key, and start calling GPT-5.2, Claude Sonnet 4.5, Gemini 3 Flash, and six more models immediately. No approval process, no waiting. One key covers every model, and the included trial credits work across all of them. Here is what most teams miss: you can test models side-by-side before deciding which one to build on.
Google AI Studio is genuinely generous. You get free access to Gemini 3 Flash with high daily request limits, multimodal support, and a massive context window. The catch: it is Gemini only. If you need GPT or Claude, you still need another provider. But for prototyping with a single model, Google's free tier is hard to beat.
Groq offers free API access to open-source models with blazing inference speed. Their custom LPU hardware delivers the fastest token generation you will find anywhere. The free tier has rate limits, but for development and testing, the speed alone makes it worth signing up.
OpenRouter provides free access to a rotating set of open-source models through an OpenAI-compatible API. The free selection changes over time and does not include frontier models like GPT or Claude. Good for experimentation, less useful if you need specific model access.
Anthropic gives new developers a $5 trial credit for Claude API access. It is enough for serious testing - roughly 2.5 million input tokens on Claude Haiku 4.5. The downside: you need a credit card on file to activate the trial. If you want Claude without a credit card, LLMWise includes it in the free tier.
Ranking evidence from practical criteria teams use for real production traffic.
For the fastest path from zero to working API call with multiple models, LLMWise covers the most ground. If you only need Gemini, Google AI Studio's free tier is honestly more generous for that single model. For raw inference speed on open-source models, Groq's free tier is unmatched. LLMWise does not have a free tier as generous as Google AI Studio for any single model, but it covers more models.
Use LLMWise Compare mode to verify these rankings on your own prompts.
Credit-based pay-per-use with token-settled billing. No monthly subscription. Paid credits never expire.
Replace multiple AI subscriptions with one wallet that includes routing, failover, and optimization.
Pricing changes, new model launches, and optimization tips. No spam.