Free AI APIs you can call from your browser
"Free API" almost never means unlimited. It means a free tier: a key that works without a card, with rate limits, and a catalogue in which some models cost nothing per token. That is enough for real work — as long as you know which part is free.
Below are the five providers our Multi-AI Search uses, why each one is there, and how to check the numbers yourself instead of trusting a blog post.
Why the browser can call them directly
Most API providers block requests coming from a web page (the CORS rules). These five allow it, which has a useful consequence: there is no server in the middle. You paste your key into the page, the key is stored in your own browser, and the request goes straight from your browser to the provider. Nothing passes through us, and we never see your key.
That also means the key is your responsibility. Treat it like a password: do not paste it into a site you do not control, and revoke it from the provider's console if you are not sure.
The five providers, and what each one is good for
| Provider | Its strong point | Use it for |
|---|---|---|
| OpenRouter | The widest catalogue of genuinely free models in one API — dozens of identifiers ending in :free. | Comparing many models at once, and trying something you have not installed. |
| Google AI Studio | A very large context window and strong multimodal reading, on a generous free tier. | Long documents, and images, audio or video inside the same prompt. |
| Groq | The fastest free inference we have tested, thanks to its dedicated chips. | Anything where waiting is annoying: drafts, chat, quick code snippets. |
| Mistral | Strong open-weight models and very good multilingual quality, from an EU provider. | Writing, coding and languages other than English. |
| Together AI | Hosts open-weight models you would otherwise have to download. | Testing Llama, Qwen or DeepSeek class models without a GPU. |
What we actually measured
On 18 October 2026 we read OpenRouter's public model catalogue through its API: 471 models listed, 19 of them priced at $0 for both input and output tokens. That is the number our search page filters on — a model counts as free only if its identifier ends in :free or both prices are exactly zero.
You do not have to take our word for it. The catalogue is public, and counting the zero-priced entries takes one request. That is the whole method: read the provider's own list, filter for zero, and show the date.
The honest caveats
- Free tiers are rate-limited. You will hit a limit if you hammer them, and free models sometimes return shorter answers than their paid siblings.
- A free model is not the flagship. Free catalogues are usually smaller or older models. They are fine for drafts, translations, extraction and tests; for the hardest reasoning, the paid version of the same family is still better.
- Keys leak if you are careless. A key in a screenshot, a public repository or a shared laptop is a key someone else can spend.
- What happens to your data is the provider's call. Some providers treat free-tier usage differently from paid usage. Read the terms before sending anything confidential, and never send what you would not want stored.
When free is not enough
Paid per-token prices are not all expensive, and the spread between models is enormous. Using the rates we read on 18 October 2026, the same job — 2 million input tokens and 0.5 million output tokens — costs:
| Model | Input / output per million tokens | Cost of that job |
|---|---|---|
| Claude Sonnet 5.5 | $2.00 / $10.00 | $9.00 |
| DeepSeek V4.1 Flash | $0.06 / $0.14 | $0.19 |
Both sets of rates come from the model catalogue; the arithmetic is (input × rate) + (output × rate). The lesson is not that one model is better — it is that "AI costs a fortune" and "AI is free" are both wrong. You can see the full picture, 24 models plus the subscription plans, in the Pricing Matrix.
Try it in about a minute
- Open Multi-AI Search.
- Add a key for one provider (OpenRouter is the quickest way to get several free models at once).
- Tick two or three models, type one prompt, and read the answers side by side — the page also shows latency, tokens and the estimated cost per model.
If you would rather not manage keys at all, the free plans in Deals & Free Tiers are the other route: a browser and an account.
Frequently asked questions
Are these APIs really free, or is it a trial?
They are free tiers, not trials with a countdown: the key works without a card, but with rate limits, and the free models are a subset of each catalogue. Limits change, so check the provider's page before you plan around them.
Do I need to install anything?
No. The search page runs in the browser, and the models run on the provider's servers. Your computer only sends the request.
Can I use this from a phone?
Yes, as long as you can paste a key into the page once. The key stays in that browser, so you would add it again on another device.
Why only five providers?
Because the others we tried refuse requests from a web page. Without a server of our own, a provider that blocks browser calls cannot be used, however good its free tier is.
Keep reading
- Multi-AI Search — one prompt, several free models, side by side.
- Pricing Matrix — what the paid models charge per million tokens.
- AI Skills Directory — the skills and MCP servers that make these models useful in your own tools.
Sources and date: the provider list and their roles come from our Multi-AI Search page; the catalogue figures (471 models, 19 at $0) and the token prices were read from the public model catalogue on 18 October 2026. Free tiers and rates change without notice.