JWT Encoder
Encode JWT header and payload JSON into a token.
Open JWT Encoder
JWT Decoder
Decode JWT header, payload, and signature parts instantly.
Related tools
More utilities that pair well with this one.
Frequently asked questions
Common questions about this tool.
It splits a token into header, payload, and signature, then decodes the Base64URL-encoded header and payload JSON directly in your browser.
No. This tool only decodes and displays data. Signature verification must be done with the correct secret or public key on trusted backend code.
JWTs must have exactly three dot-separated parts. If any part is missing, badly encoded, or if header/payload are not valid JSON, decoding fails.
JWTs use URL-safe Base64 (Base64URL): it replaces + and / with - and _, and padding may be omitted. Decoders normalize these differences before parsing.
Treat tokens as sensitive. Anyone with a valid unexpired token may access protected resources, so avoid sharing real tokens in screenshots, logs, or chats.
Common claims include iss (issuer), sub (subject), aud (audience), exp (expiry), iat (issued at), and custom app-specific claims for roles or permissions.