🔐 Developer Tools
Build and sign a JSON Web Token in seconds. Edit the header and payload, pick an algorithm, add your secret or private key, and get a ready-to-use signed JWT — all privately in your browser.
HMAC uses a shared secret. Switch algorithm to RS/PS/ES to sign with a PEM private key.
Generate signed tokens with the Web Crypto API — no server, no libraries, no exposure of your keys.
HMAC (HS), RSA (RS/PS), and ECDSA (ES) are all supported for real, verifiable signatures.
Add iat, exp, and nbf with one click, and format your JSON instantly.
Your secret, private key, and generated token never leave your device.
ToolAdda base64url-encodes your header and payload, joins them with a dot, and signs that string with your secret or private key using the selected algorithm. The signature is appended to produce a complete header.payload.signature token that other services can verify.
All signing happens locally in your browser. Your secret, private key, payload, and generated token are never uploaded, logged, or stored on any server.
Pick an algorithm, edit the payload with your claims, enter your secret or private key, and the signed token appears instantly on the right.
Yes. Signing runs entirely in your browser with the Web Crypto API — nothing is sent anywhere.
A PEM private key in PKCS#8 format (begins with -----BEGIN PRIVATE KEY-----).
Yes — open it in our JWT Debugger and check the signature with the matching secret or public key.
No. The payload is only encoded, not encrypted, so anyone can read it. Keep only non-sensitive claims.
HS256 is common for simple shared-secret setups; RS256 and ES256 are preferred when different parties verify with a public key.
The JWT Encoder by ToolAdda lets developers quickly craft and sign JSON Web Tokens for testing authentication, APIs, and integrations. Edit the claims, choose the signing algorithm, and generate a valid token you can paste into requests or verify elsewhere — without installing anything or exposing your keys to a server.