JWT Decoder Tool

Real-time JSON Web Token analysis, validation, and debugging

Enter JWT Token
Enter a JWT token to decode it in real-time. The token will be automatically analyzed as you type.
Header
Header will appear here after decoding...
Algorithm: Not detected
Token Type: Not detected
Payload
Payload will appear here after decoding...
Issued At: Not detected
Expiration: Not detected
Signature & Validation
Signature will appear here after decoding...
Token Status:
Not validated
Advanced Features
Real-time Decoding

Automatically decode JWT tokens as you type with instant feedback.

Token Validation

Validate token structure, expiration, and required claims automatically.

Expiry Check

Check token expiration status with visual indicators and time remaining.

Error Detection

Detect common JWT errors like malformed tokens and invalid claims.

Base64 Decoding

Automatically decode Base64Url encoded header and payload sections.

Claim Analysis

Analyze standard JWT claims like sub, iss, aud, exp, iat, and nbf.

Export Results

Export decoded results as JSON, text, or copy to clipboard with one click.

Pretty Display

Beautifully formatted JSON output with syntax highlighting for readability.

Algorithm Detection

Detect and display the encryption algorithm used in the JWT token.

Signature Analysis

Analyze token signature format and provide verification options.

Complete Decoded Output
Complete decoded JSON will appear here...
0 characters | 0 parts

How to Use the JWT Decoder Tool: A Complete Guide

Our JWT Decoder Tool provides a simple yet powerful way to analyze and debug JSON Web Tokens. Whether you're a developer troubleshooting authentication issues or a security professional examining tokens, this tool makes the process straightforward.

Step-by-Step Instructions:

  1. Paste your JWT token into the input field at the top of the page. You can use the "Load Sample Token" button to see an example.
  2. The tool will automatically decode the token in real-time as you type, displaying the header, payload, and signature sections separately.
  3. Review the Header section to see the token type and encryption algorithm used (like HS256, RS256, etc.).
  4. Examine the Payload section to view all claims contained in the token, including standard claims like:
    • sub (subject) - The user or entity the token represents
    • exp (expiration) - When the token expires
    • iat (issued at) - When the token was issued
    • iss (issuer) - Who issued the token
    • aud (audience) - Who the token is intended for
  5. Check the Signature section to verify the token's integrity. Use the "Validate Token" button to check for common issues.
  6. Use the Advanced Features to export results, copy to clipboard, or analyze specific token properties.

Understanding JWT Tokens:

JSON Web Tokens (JWT) are an open standard for securely transmitting information between parties as a JSON object. They consist of three parts separated by dots:

  1. Header - Contains the token type and the signing algorithm being used
  2. Payload - Contains the claims (statements about an entity and additional data)
  3. Signature - Used to verify that the sender is who they say they are and to ensure the message wasn't changed along the way

Common Use Cases:

Pro Tip: This tool only decodes tokens - it doesn't verify cryptographic signatures without the secret key. For full signature verification, you'll need to use the appropriate verification library with your secret key.