You can build and ship a real LLM-powered product in 2026 without paying for inference, if you know which providers hand out free keys and what each one's catch is. There are three flavors: permanent free tiers (rate-limited but renewable forever), one-time trial credits (a fixed budget that runs out), and free model routes on aggregators. This is the current list, in rough order of usefulness.
Permanent free tiers
These renew on their own. Rate limits are the constraint, not a countdown.
- Google AI Studio (Gemini): the most generous free tier in the business. Free access to Gemini models with daily request caps that comfortably cover prototyping and small internal tools. The catch: your data may be used for product improvement on the free tier, so keep sensitive content out.
- Groq: free tier with fast open-model inference (Llama, gpt-oss and friends) at interactive speeds. Tight per-minute caps, generous per-day ones. Great default for agents in development.
- Mistral La Plateforme: a free tier for their hosted models, good enough to evaluate the whole Mistral lineup before committing.
- Cerebras: free tier serving open models at extremely high tokens-per-second. Same pattern: fine for development, capped for production.
- Cohere: a trial key with monthly request allowances on Command models, aimed at evaluation rather than production.
A free key on a fast open-model host covers most development loops entirely. Save the paid keys for production traffic.
One-time signup credits
Small budgets, but they stack, and no card is usually required:
- xAI: signup credit for the Grok API, enough for a serious evaluation of Grok 4 Fast, which is unusually cheap to begin with.
- SambaNova: a few dollars of credit on their high-speed open-model cloud.
- Novita: signup and referral credits on a large open-model catalog.
- Fireworks: a small starter credit, enough to benchmark their serverless endpoints.
Bigger one-time credits exist at the platform level (OpenAI, Anthropic, and Google all run startup programs measured in thousands of dollars), but those are applications, not signups. The startup credits checklist covers that tier, and every program lives in the catalog with a claim guide.
Free model routes on OpenRouter
OpenRouter lists rotating free variants of popular open models: the same weights, served at zero cost with tighter rate limits and queue priority below paid traffic. One key, many models, and your code does not change when you later swap the free route for a paid one. We break down when the aggregator premium is worth it in OpenRouter vs direct.
What the free keys are actually good for
| Use case | Best free option | When you outgrow it |
|---|---|---|
| Prototyping an agent | Groq or Cerebras free tier | Per-minute rate caps |
| Evaluating model quality | Google AI Studio | Data-use terms, caps |
| Side project in production | Gemini free tier plus a free OpenRouter route | Reliability needs |
| Benchmarking before buying | Trial credits (xAI, Novita, Fireworks) | Credits run out |
The honest answer on production: free tiers carry no SLA, and free OpenRouter routes can queue behind paid traffic. The moment real users depend on a response, you want a paid key on the cheapest solid host for your model, which is exactly what the live rankings track per model, updated weekly.
How to stack this properly
- Develop against a fast free tier (Groq, Cerebras, or Gemini).
- Evaluate candidates with trial credits so the bake-off costs nothing.
- Ship on the cheapest paid endpoint for your chosen model from the rankings.
- Claim the platform startup credits in parallel, because approvals take days and the amounts dwarf every free tier combined. Start with free AI API credits.
Bottom line
Between Gemini's free tier, Groq and Cerebras speed, Mistral and Cohere evaluation keys, small signup credits, and OpenRouter free routes, inference for development is effectively free in 2026. Treat free tiers as your dev environment, trial credits as your bake-off budget, and the catalog as the map to the thousands of dollars in startup credits that come next. Create an account to see every verified offer.
Related reading: Groq's free tier, Gemini API free access, Mistral's free tier.