Developer tool · Free · No sign-up

JWT Decoder

Instantly decode, verify, and inspect JSON Web Tokens securely in your browser.

Encoded Token

Token Inspector

Paste a token to inspect its contents.

About this tool

JSON Web Tokens (JWT) are an industry standard for securely transmitting information between parties as a JSON object. This tool allows you to paste a JWT and instantly decode its Header, Payload, and Signature to verify claims, expiration dates, and algorithms.

Key features

100% Client-Side

Your tokens are decoded instantly in your browser. No data is ever sent to a server.

Smart Timestamp Parsing

Automatically converts 'exp', 'iat', and 'nbf' Unix timestamps into readable dates.

Syntax Highlighting

Clean, formatted JSON output makes it easy to read complex payloads.

How to use it

1Copy your JSON Web Token string.
2Paste the token into the input area.
3The tool will instantly decode and separate the Header, Payload, and Signature.
4Review the parsed data and check the expiration status.

Common use cases

Debugging authentication issues by verifying token expiration.
Checking user roles or permissions embedded inside a token payload.
Verifying which signing algorithm was used.

Frequently asked questions

Is it safe to paste my JWT here?

Yes. This tool runs 100% in your local browser. Your token is never transmitted to any external server.

Can this tool verify the signature?

This tool decodes the token for inspection. Validating a signature requires your private secret key, which should never be used in a public web tool.

Why is my token failing to decode?

A valid JWT must contain exactly three base64-encoded segments separated by dots (.). If your string lacks these, it is not a valid JWT format.

Private and free. Most of our tools run entirely in your browser, so the data you enter isn't uploaded or stored. There's no sign-up, and there never will be — they're built by the Fusion Trail Solutions team to be genuinely useful.