| API | Category | Free tier | No CC | Commercial |
|---|
⚠️ Free tiers and terms change often. Limits and credit-card / commercial-use flags are reference values (June 2026) — always confirm in the provider's current docs before relying on them in production.
How to read this
"Free forever" means an ongoing free allowance, not a time-limited trial. "Trial credits" are one-off dollars or a window that expires. "No CC" means you can start without entering a card — the fastest path to a working key for prototypes and side projects. "Commercial" flags whether the free tier is generally okay to ship in a paid product; when in doubt, the provider's terms win.
Found one you like? Many have a full guide here with pricing and step-by-step key setup — see OpenAI, Gemini, Twilio, SendGrid, CoinGecko and the rest. Planning what it'll cost once you outgrow the free tier? Use the API stack cost calculator.