JWT Decoder
Inspect the header and payload of a JSON Web Token locally. Decoding does not verify its signature.
Decoded content is untrusted until the token signature and claims are verified by your application.
Decode JWT headers and payloads
A JSON Web Token commonly contains a Base64URL-encoded header, payload and cryptographic signature separated by periods.
Reading the header and payload does not prove the token is authentic. Secure applications must validate the signature, issuer, audience and time-based claims.
How to use the JWT Decoder
- Paste or select the source value in the expected format.
- Choose the conversion direction or output format and run the conversion.
- Review and copy the converted value, then verify it in the receiving application.
Practical example
Use a small known sample first so you can compare the output before processing a larger value.
What this tool cannot guarantee
The result reflects the supplied input and browser implementation; project-specific syntax and runtime behavior still require testing.
Continue this workflow with the Base64 Encoder & Decoder
Frequently asked questions
Is the JWT Decoder free to use?
Yes. It is available without an account or paid subscription.
Is my input uploaded or stored?
The core operation runs in your browser. Avoid pasting secrets into any web page unless the individual tool explicitly explains how the data is handled.
Should I review the result before using it?
Yes. Check the output for your project and test it in the intended environment before production use.