DEVELOPER TOOL

Decode a JWT header and payload in your browser.

Inspect the readable JSON parts of a JSON Web Token without sending it to a server. Signature verification is intentionally not claimed or performed.

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LOCAL BROWSER TOOL

Run the tool

Paste a three-part JWT to decode its Base64URL header and payload.

JWT input

Second input

Decoded token

HOW IT WORKS

Decoding reveals claims; it does not prove authenticity.

A compact JWT contains Base64URL-encoded header and payload sections followed by a signature. Reading the first two sections is useful for debugging, but only cryptographic verification with the correct key can establish trust.

Your data stays local

The transformation runs in this browser tab. ClearText Tools does not upload the input to a processing server.

Review the output

Copy the result only after checking structure, edge cases and any values that affect production systems.

Known boundaries

A decoded token is not a verified token
Do not paste live secrets unnecessarily
Encrypted JWE tokens are not supported

NEXT TASK

Continue this workflow

Use a related tool or guide when the result needs another cleanup, validation or conversion step.

Base64 encoder JSON formatter Timestamp converter JWT decoding guide

Common questions

Is my input uploaded?

No. This tool processes the input locally in your browser.

Can I use the result without checking it?

Use it as a fast transformation, then validate important output against the requirements of the destination system.