How to use the JWT Decoder
- Enter or paste your input in the tool above.
- Choose the available options and select Run tool or Process locally.
- Review, copy, or download the generated result.
What does the JWT Decoder do?
A JSON Web Token normally contains Base64URL-encoded header, payload, and signature segments. Decoding reveals readable claims, but it does not prove that the token was issued by a trusted party or has not been modified.
Common uses
- Inspect authentication claims during development
- Check exp, iat, iss, aud, and scope values
- Debug token formatting and Base64URL payloads
JWT Decoder example
Example input
eyJhbGciOiJub25lIiwidHlwIjoiSldUIn0.eyJzdWIiOiI0MiIsInJvbGUiOiJlZGl0b3IifQ.Example output
{
"header": { "alg": "none", "typ": "JWT" },
"payload": { "sub": "42", "role": "editor" },
"signature": ""
}Limitations and important notes
- Decoded output is not signature verification
- Claims can be forged in an untrusted token
- Production access tokens should not be pasted into online services
Private browser-based processing
Your data is processed locally in your browser and is not uploaded or stored on our servers. Tool inputs are not saved to local storage.
JWT Decoder features
- Free to use with no registration
- Fast client-side processing
- Clear validation and useful error messages
- Copy and download support
- Mobile-friendly accessible interface
Frequently asked questions
Does decoding a JWT verify that it is genuine?
No. Verification requires the expected algorithm and a trusted secret or public key.
Is JWT payload data encrypted?
Usually not. Standard JWT payloads are encoded and can be read by anyone who has the token.
Is the JWT Decoder free to use?
Yes. The JWT Decoder is completely free and requires no account or installation.
Is my data uploaded when using JWT Decoder?
No. Your input and result are processed locally inside your browser and are not sent to our server.
Can I use JWT Decoder on mobile?
Yes. The tool works in modern desktop and mobile browsers.