JWT Toolkit

Zero-dependency JWT decoder and inspector. Decodes any JWT token and shows header, payload claims, algorithm info, expiry status, and signature details.

Quick Start

# Decode a JWT token
python3 scripts/jwt_decode.py eyJhbGciOiJIUzI1NiIs...

# Read token from file
python3 scripts/jwt_decode.py --file token.txt

# Read from stdin (pipe from curl, etc.)
echo "eyJ..." | python3 scripts/jwt_decode.py --stdin

# JSON output for scripting
python3 scripts/jwt_decode.py eyJ... --format json

# Also handles "Bearer " prefix automatically
python3 scripts/jwt_decode.py "Bearer eyJhbGciOiJIUzI1NiIs..."

Features

• Decodes header and payload with human-readable claim labels
• Shows algorithm details and security warnings (e.g., none algorithm)
• Checks token expiry with remaining time or time-since-expired
• Recognizes 20+ standard and common claims (iss, sub, aud, roles, scope, etc.)
• Strips "Bearer " prefix automatically
• JSON and text output formats
• No external dependencies — pure Python stdlib