JWT

JWT Decoder

Decode and inspect JSON Web Tokens without sending them to a server

JWT Token

Was this tool helpful?

What is JWT Decoder?

Free online JWT decoder to decode JSON Web Tokens (JWT) instantly in your browser.

Paste a JWT and see the decoded header, payload, and signature. The tool shows the algorithm used, all claims including expiration time, and whether the token is still valid. Perfect for debugging authentication flows, inspecting API tokens, and understanding JWT structure. Your tokens never leave your browser - everything is decoded locally. No signup required.

How to Use JWT Decoder

1Paste your JWT token into the input field
2Click 'Decode' to parse the token
3Review the decoded header (algorithm, type) and payload (claims, expiration)
4Copy individual sections or check the token's expiration status

Frequently Asked Questions

A JSON Web Token (JWT) is a compact, URL-safe token format used for securely transmitting information between parties. It consists of three parts separated by dots: a header (algorithm and type), a payload (claims/data), and a signature. JWTs are commonly used for authentication and authorization in web applications.

Yes. This tool decodes JWTs entirely in your browser using JavaScript. The token is never sent to any server. However, remember that JWTs are only encoded (not encrypted), so anyone with the token can read its contents.

This tool decodes and displays the JWT contents but does not verify signatures, as that requires the secret key or public key used to sign the token. It is designed for inspection and debugging, not for security validation.

Common claims include: iss (issuer), sub (subject), aud (audience), exp (expiration time), nbf (not before), iat (issued at), and jti (JWT ID). Custom claims can contain any application-specific data.

Share this tool

Related Tools

Explain This

Free online explain this - paste any input and get a human-readable explanation of what it is

🪝

Webhook Tester

Webhook tester online - generate temporary webhook URLs and inspect incoming HTTP requests for free

{ }

JSON Formatter

JSON formatter and validator online - format, beautify, and validate JSON data instantly in your browser

$..

JSON Path Finder

Free online JSON path finder - navigate JSON and click to copy the path to any value

B64

Base64 Encoder/Decoder

Base64 encode and decode online - convert text to Base64 or decode Base64 strings instantly, free

%20

URL Encoder/Decoder

Free online URL encoder/decoder - encode or decode URL components for safe web usage

JWT