⚡ JavaScript Tool
JWT Decoder
Decode a JWT header and payload so claims, expiry, issuer, audience, and token metadata can be inspected quickly.
Interactive Tool
Use JWT Decoder
How to use JWT Decoder
- Paste the full JWT string from an authorization flow, request, or log entry.
- Decode the token and review the header and payload sections separately.
- Check timestamps and claims, but verify signatures in your application or auth provider before trusting the token.
Why use JWT Decoder
JWTs are compact, which makes them awkward to read during debugging. Decoding the header and payload helps you see algorithm hints, subject IDs, scopes, expiry times, issuer values, and other claims that affect authentication behavior.
This decoder is for inspection, not trust decisions. A decoded token can still be expired, tampered with, or signed by the wrong issuer. Always let the server-side verification code decide whether a JWT is valid.
Best for JWT Decoder
- Debugging login and API authorization issues.
- Checking expiry and issued-at timestamps.
- Inspecting scopes or roles carried in a token.
Practical notes
- Do not paste sensitive production tokens into shared machines.
- Signature verification must happen outside this viewer.
- Check clock differences when investigating expiry problems.