JWT Decoder

Developer Tools

Decode and inspect JWT tokens — header, payload, and signature.

JWT Token

What is JWT Decoder?

A JWT Decoder is a browser tool that splits a JSON Web Token into its three Base64URL-encoded parts — header, payload, and signature — and decodes them into readable JSON. It also shows the token's expiry status, algorithm, and standard claim explanations.

How to use JWT Decoder

Paste the JWT

Copy a JWT from your browser's developer tools, Postman, or code and paste it into the input field.

Review the status bar

The coloured status strip instantly shows whether the token is valid, expired, or not yet valid, along with how much time remains.

Inspect header & payload

Switch between the Header, Payload, and Signature tabs to read the decoded JSON with full syntax highlighting.

Understand claims

Each standard claim (iss, sub, aud, exp, iat) is annotated with a plain-English description so you know what it means.

Who uses JWT Decoder?

Authentication debugging

Backend developers

Quickly check what claims are inside a JWT returned by your auth server — user ID, roles, expiry — without writing any decode code.

Security reviews

Security engineers

Inspect JWTs in HTTP traffic to verify the algorithm (e.g. RS256 vs HS256) and ensure sensitive data is not accidentally exposed in the payload.

API integration testing

Frontend developers

Decode tokens retrieved via OAuth flows to confirm the scopes, audiences, and user information match what your app expects.

Related Tools

JSON Formatter

Format, validate, and beautify JSON with syntax highlighting.

Secure Hash Generator

Generate MD5, SHA-1, SHA-256, SHA-512 and other cryptographic hashes.

Encoder / Decoder

Encode and decode Base64, URL, HTML, Unicode, and more.

JSON to CSV Converter

Convert JSON arrays to CSV and CSV back to JSON bidirectionally.

FAQ

Is it safe to paste my JWT token here?+

The decoding happens entirely in your browser — no data is sent to any server. However, never share your JWT in public environments as it contains authentication data.

Can this tool verify JWT signatures?+

Currently the tool decodes and displays JWT contents. Signature verification requires your secret key, which we deliberately do not request for security reasons.

What JWT algorithms are supported?+

The decoder supports all standard JWT algorithms: HS256, HS384, HS512, RS256, RS384, RS512, ES256, ES384, ES512, and PS algorithms.