JWT Decoder

What is the JWT Decoder Tool?

The JWT Decoder is a free online tool that decodes and analyzes JSON Web Tokens (JWTs). It breaks down JWT tokens into their three components - header, payload, and signature - and provides detailed information about each claim, including standard claims like expiration time, issuer, and subject.

Why Use Our JWT Decoder?

• Debug Authentication Issues: Quickly inspect JWT contents when troubleshooting login or authorization problems
• Verify Token Structure: Ensure your JWTs contain the expected claims and values
• Check Token Expiration: Instantly see if a token has expired or will expire soon
• Learn JWT Structure: Understand how JWTs work by seeing their decoded components
• Privacy First: All decoding happens locally - your tokens never leave your browser

Key Features

• Complete Token Analysis: Decode header, payload, and verify signature presence
• Claim Descriptions: Understand what each standard JWT claim means
• Timestamp Conversion: Automatically converts Unix timestamps to readable dates
• Validity Checking: Shows whether the token is expired or not yet valid
• Sample Token: Try with a demo token to learn how JWTs work
• Algorithm Detection: Identifies the signing algorithm used (HS256, RS256, etc.)

How to Use

1. Paste your JWT token in the input field (Bearer prefix is automatically removed)
2. Click "Decode Token" to analyze the JWT
3. Review the decoded header, payload claims, and signature information
4. Check the analysis for expiration status and warnings

Common JWT Claims Explained

• iss (Issuer): Who created and signed the token
• sub (Subject): The user or entity the token represents
• aud (Audience): The intended recipient of the token
• exp (Expiration): When the token expires
• iat (Issued At): When the token was created
• nbf (Not Before): Token is not valid before this time

Frequently Asked Questions

Is it safe to paste my JWT here?

Yes! The decoding happens entirely in your browser. Your tokens are never sent to any server or stored anywhere.

Can this tool verify my JWT signature?

This tool only decodes the token to show its contents. Signature verification requires the secret key, which should never be shared.

What algorithms are supported?

We support decoding tokens signed with any algorithm including HS256, HS384, HS512, RS256, RS384, RS512, ES256, ES384, ES512, and more.