Free online JWT decoder. Decode JWT tokens to view header and payload as formatted JSON. Supports base64url encoding. Runs locally in your browser, no data uploaded.
100% Local
How to Use the JWT Decoder
Paste a JWT token into the input box. Click Decode JWT and the header and payload are decoded from base64url and displayed as formatted JSON. The signature is shown as-is. Use Clear to reset.
What the decoder does
Splits the token on dots into header, payload and signature
Decodes each base64url-encoded segment to UTF-8
Parses the header and payload as JSON and pretty-prints them
Shows the signature part unchanged (verification requires the secret)
Features
Supports standard base64url encoding with padding restoration
Works with standard and compact JWT formats
No token verification — decoding only (verification needs the secret key)
All processing runs locally in your browser. Your data is not uploaded to any server.