JWT Encoder & Signer
Build and sign a JWT — pick HS256 / HS384 / HS512, paste a header and payload (JSON), provide your secret, get a signed token. Uses Web Crypto API; your secret never leaves the browser.
How to use JWT Encoder / Signer
- Set algorithm + secret.
- Type or paste the header and payload JSON.
- Click Encode JWT.
- Copy the signed token.
What is JWT Encoder / Signer?
Useful for testing API endpoints that expect signed JWTs. The signing happens in-browser via the Web Crypto API's HMAC subtle.sign call. For RS256/ES256 (asymmetric) signing, you'd need a separate key management flow — those aren't supported yet.
FAQ
- Is my secret sent anywhere?
- No — all signing is local via Web Crypto. The secret stays in memory.
- Does it support RS256 / ES256?
- Not yet — only HMAC variants. RSA / ECDSA require private-key management.
Related tools
People also use
- HTML Table Generator🗄️ Developer Tools
Generate HTML table markup from delimited text data. Supports tab, comma, CSV, and custom delimiters. Free online HTML table generator.
- JSON to TypeScript🗄️ Developer Tools
JSON to TypeScript — Paste a JSON payload and instantly get TypeScript interfaces (or type aliases) describing its shape. Optionally mark all properties...
- BBCode to HTML🔄 Transformation
Free online BBCode to HTML converter. Convert BBCode tags like [b], [i], [url], [img], [quote], [list], [color], and more to clean HTML markup.
Last updated: