JWT Debugger
Editor
Summary
Algorithm
Verification
Signature
exp
nbf
iat
Warnings
Decoded token
What is a JWT Debugger?
A JWT debugger helps you inspect JSON Web Tokens by decoding the header and payload, checking claims, and validating the signature when a secret or key is available.
It is useful for authentication debugging, API testing, expiration checks, and quickly editing payload data during development.
How to use the JWT Debugger
- Paste a JWT token into the token field.
- Optionally enter the secret or key and choose the algorithm.
- Click Analyze to inspect claims and validation results.
- Edit header or payload JSON and generate a new token if needed.
Tips
- JWT payload data is only encoded, not encrypted.
- Always verify expiration and not-before claims when debugging auth issues.
- Use the same algorithm and secret as your backend when validating signatures.
- Do not paste production secrets unless you fully trust the environment.
Related tools
You may also find these tools useful.
JWT Decoder
Decode JWT header and payload instantly in your browser.
Encoding & Security
›
JWT Encoder (HS256)
Generate signed JWT tokens using HS256 (HMAC SHA-256) directly in your browser.
Encoding & Security
›
HMAC Generator
Generate HMAC-SHA-256, SHA-1, and SHA-512 signatures instantly in your browser.
Encoding & Security
›
Base64 Encoder / Decoder
Encode and decode Base64 online instantly. Free Base64 converter with no login.
Encoding & Security
›
JWT Debugger FAQ
Can this tool validate JWT signatures?
Yes, when you provide the required secret or key and the token uses a supported algorithm.
Can I edit and regenerate a JWT?
Yes. You can modify the header and payload JSON, then generate a new token.
Does it show expiration details?
Yes. The debugger can show whether a token is expired and help inspect time-related claims.
Is my token sent to a server?
That depends on your implementation. If your setup validates on the backend, do not use production secrets unless you trust the environment.