JWT Encoder/Decoder

About

JWT Tool - Advanced Encoder/Decoder Extension
Overview:
A powerful developer tool for inspecting, validating, and manipulating JSON Web Tokens directly in your browser. This extension provides complete JWT handling capabilities with robust security features.

Key Features:
Instant Decoding: Break down JWT tokens into header, payload, and signature components
Smart Validation: Automatic checks for expiration, validity periods, and issuance dates
Realtime Encoding: Generate new tokens with multiple algorithm support (HS256/384/512, RS256/384/512, ES256/384/512,none)
Signature Verification: Validate token signatures against provided keys
Secure Handling: All processing occurs locally - no token data leaves your browser
Developer-Friendly: Clean interface with syntax-highlighted JSON views

Technical Specifications:
Supports all standard JWT algorithms (HMAC, RSA, ECDSA)
Clipboard integration for easy token pasting/copying
Comprehensive token validation including:
Expiration (exp)
Not Before (nbf)
Issued At (iat)
Manifest v3 compliant
Zero external dependencies (except jsrsasign library bundled locally)

Security Notice:
This tool is designed for development purposes only. We strongly recommend:
Never using production secrets
Always working in secure environments
Verifying tokens contain no sensitive data before processing

Ideal For:
API developers
Security researchers
Quality assurance testers
Authentication system debuggers