JWT Decoder
Decode JSON Web Tokens.
100% private Runs locally No sign-up
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Heavy libraries load on demand so the page shell stays fast.
About JWT Decoder
JWT Decoder inspects JSON Web Token headers and payloads in the browser. Debug auth issues without pasting production tokens into a public decoder that might log them.
How to use JWT Decoder
- 1Paste the JWT (header.payload.signature).
- 2Decode to view claims locally.
- 3Check exp/nbf/aud and custom claims against your API expectations.
- 4Never share screenshots that include live access tokens.
Frequently asked questions
Does decode verify signatures?
Decoding reads claims; verification needs the secret/key and should happen on a trusted server.
Safe to paste prod tokens?
Prefer redacted or expired tokens. Local decode still risks shoulder-surfing and screen shares.
Encrypted JWTs (JWE)?
This tool targets compact JWS-style JWTs. Encrypted tokens need different handling.
Encode a test token?
Use JWT Encoder for non-production experiments only.
Base64url vs Base64?
JWTs use base64url. The decoder expects standard JWT serialization.