Developer Tools
JWT Decoder
Paste a JSON Web Token and instantly see the decoded header, payload, and signature breakdown. The decoder shows all claims, checks the expiry timestamp, and explains the algorithm, without sending your token anywhere.
Paste a JWT token above to decode it
Decoded locally in your browser; your JWT token is never sent anywhere
Features
- Decodes JWT header, payload, and signature sections
- Shows all claims including exp, iat, sub, aud in readable format
- Expiry check, highlights if the token is expired
- Algorithm and token type shown prominently
- Timestamp claims converted to human-readable dates
- Token never sent to any server, decoded locally
How to use it
- Paste your JWT (the full eyJ... string) into the input.
- Header and payload sections appear decoded immediately.
- Check the expiry panel to see if the token is still valid.
- Review claims to debug auth issues or inspect token contents.
Use cases
- Debugging authentication issues in development
- Inspecting what claims a third-party token contains
- Checking token expiry without running code
- Reviewing access scopes in OAuth2 tokens
Limitations
- JWTs can contain sensitive data. This tool decodes only and does not verify signatures.
- Very large input can be slower on older devices.
- This utility is designed for common snippets and local inspection, not as a full security or language-specific validator.
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Use toolFrequently asked
Does it verify the JWT signature?
No, signature verification requires the secret key or public key, which you should never enter into a web tool. This tool only decodes the visible parts.
Is it safe to paste production JWTs here?
The token is decoded entirely in your browser and never uploaded. However, for production secrets you should treat tokens with the same caution as passwords.