JWT Decoder
Decode and inspect JSON Web Token header, payload and signature. All processing is 100% local.
Header
Waiting for token…
Payload
Waiting for token…
Signature
Waiting for token…
How it works
1
Paste your JWT
Copy a JWT token (the three Base64URL parts separated by dots) and paste it into the textarea.
2
Instant decode
The tool splits the token and Base64URL-decodes each part live as you type, showing Header and Payload as formatted JSON.
3
Inspect claims
Expiry (exp) and issued-at (iat) timestamps are detected automatically and shown with a validity badge.
4
Copy any section
Use the Copy button on each panel to copy the Header JSON, Payload JSON, or the raw Signature string to your clipboard.