JWT Generator Online — Sign & Verify HS256 — Free & Private

A free edge API by formatho.com, privacy-first developer tools.

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Free, no signup, runs entirely in your browser — your data never leaves your device.

🔓 Free 🔒 Zero tracking 🚫 No data collection ⚡ Edge-fast

Usage

curl "https://jwt-generator-formatho.filesformatho.workers.dev/api?secret=your-256-bit-secret&payload=%7B%22sub%22%3A%22123%22%7D&exp_in=3600"
curl -X POST "https://jwt-generator-formatho.filesformatho.workers.dev/api"   -H "Content-Type: application/json"   -d '{"secret":"s3cr3t","payload":{"sub":"user-1","role":"admin"},"exp_in":3600}'
curl "https://jwt-generator-formatho.filesformatho.workers.dev/api?token=eyJhbGciOiJIUzI1NiJ9...&secret=s3cr3t"

Full parameter reference and live response: /api endpoint.

What is a JWT?

A JSON Web Token (RFC 7519) is a compact, URL-safe way to represent signed claims between two parties. It has three base64url segments — header.payload.signature — where the header names the algorithm, the payload carries claims like sub, exp or role, and the HMAC signature proves the token was created by someone holding the secret. This tool signs and verifies symmetric HS256/HS384/HS512 tokens with the Web Crypto API on the edge; for production, prefer short expiry times and long random secrets.

Privacy-first: every request is processed in-memory on Cloudflare's edge and answered immediately. No logs, no analytics, no cookies, no data collection. See the Formatho privacy philosophy.

Full browser tool

Prefer a UI? Use the complete client-side version — signing happens right in your browser: JWT suite on formatho.com. Just need to read a token? See the JWT Decoder.

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