JWT Decoder & Generator
Decode JWT tokens securely in your browser. Validate claims, check expiration dates, and generate signed tokens for testing without server communication.
Encoded Token
{
...
}{
...
}Want to learn more about JSON Web Tokens?
Related Tools
More tools in this category that you might find useful.
How to use JWT Decoder & Debugger
Paste your complete JSON Web Token (JWT) into the encoded text area.
The tool will instantly parse the token and separate it into its three components: Header, Payload, and Signature.
Read the decoded JSON payload to verify claims, user IDs, expiration times (exp), and issued-at times (iat).
Why use our JWT Decoder & Debugger?
Instant Claim Parsing
Automatically translates common claims like 'exp' (Expiration) and 'iat' (Issued At) from Unix timestamps into human-readable dates.
Zero-Server Transmission
Tokens often contain sensitive authentication data. Our decoder runs entirely in your browser using JavaScript, ensuring your tokens are never logged.
100% Secure & Private
All processing happens in your browser. Your files are never uploaded to our servers, guaranteeing absolute privacy and security.
Lightning Fast
Because everything runs locally on your device, processing is instant. No waiting in queues or dealing with slow uploads.
Frequently Asked Questions
Can I use this tool to verify the JWT signature?
Currently, this tool acts as a decoder, meaning it reads the Base64Url encoded Header and Payload. It does not verify the cryptographic signature against a secret key.
Is it safe to put sensitive data in a JWT payload?
No! The payload of a standard JWT is only Base64 encoded, not encrypted. Anyone who intercepts the token can decode it (using a tool like this) and read the contents. Only put public claims (like User ID or Role) inside a JWT.
What happens if a JWT expires?
The 'exp' claim defines the expiration time. If a server receives a token where the current time is past the 'exp' time, the server will reject the token with a 401 Unauthorized error.
Share this Tool
Related Guides & Strategies
Learn how to get the most out of this tool.
How to Decode and Verify JSON Web Tokens (JWT)
Understand JWT structure (Header, Payload, Signature) and how to decode them securely.
Ultimate Guide to Using the JWT Decoder (Free Tool)
Learn how to use our free JWT Decoder to streamline your workflow. Decode JWT headers, payload JSON, check expiration and signature status....