PlayWithJSON – JWT Decoder

Fast, clean, developer-focused JWT decoder, active tab token inspector, and live expiry tracker from PlayWithJSON.

PlayWithJSON JWT Decoder is a fast, clean, and developer-focused browser extension for decoding, inspecting, extracting, and tracking JSON Web Tokens (JWTs) in real time. Decode JWT tokens instantly, inspect their Header and Payload claims, monitor live token expiry countdowns, and extract active session tokens directly from your web apps in zero clicks. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✨ KEY FEATURES ━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🔍 1-Click Active Tab Token Extraction: • Instantly detect and extract JWT access tokens from the active browser tab (localStorage, sessionStorage, and cookies). • No more manual digging through Chrome DevTools Application tabs during API debugging. ⚡ Zero-Click Auto-Decode on Paste: • Just paste your token — it automatically cleans any "Bearer " prefixes and decodes the token instantly. • Keyboard shortcut support: Press Cmd/Ctrl + Enter to decode anytime. ⏳ Live Expiry Countdown & Timeline Progress Bar: • Real-time countdown timer showing remaining validity (days, hours, minutes, and seconds). • Pulsing live visual indicators: Active (Green), Expiring Soon (<5 mins, Amber), and Expired (Red). • Dynamic timeline progress bar illustrating the percentage of the token's lifetime elapsed. 📋 One-Click Developer Copy Tools: • "Copy as Bearer": Copies `Bearer <token>` ready for authorization headers. • "Copy as cURL Header": Copies `-H "Authorization: Bearer <token>"` directly into your clipboard for terminal or Postman testing. • Independent 1-click copy buttons for Header JSON, Payload JSON, and raw Signature. 🕒 Recent Tokens History (Last 5 Tokens): • Automatically saves your last 5 decoded tokens in local browser storage. • Displays algorithm (HS256, RS256, ES256, etc.), token subject/user, validity badges, and timestamps. • 1-click to instantly reload any past token back into the inspector. Includes a clear history option. 🎨 Syntax Highlighting & Line Numbers: • Beautiful color-coded JSON formatting for Header and Payload claims. • Line numbering for effortless inspection and debugging. 🌓 Dark & Light Mode: • Built-in theme switcher matching the modern design system of PlayWithJSON. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🔒 100% CLIENT-SIDE & PRIVACY FIRST ━━━━━━━━━━━━━━━━━━━━━━━━━━━━ • All decoding is performed 100% locally in your browser using standard client-side Base64URL decoders. • Your tokens never leave your machine and are never transmitted to external servers or logged. • Permissions are strictly limited to active-tab token extraction only when you explicitly click the Extract button. • No account, registration, or sign-in required. • Works completely offline. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 💡 DESIGNED FOR DEVELOPERS ━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Whether you are debugging web applications, inspecting API authentication workflows, or troubleshooting token expiration, PlayWithJSON JWT Decoder gives you a fast, secure, and offline environment to inspect tokens directly in your browser. Learn more and explore the full developer toolkit at https://playwithjson.com.