JWT Decoder
JWT Decoder
Parse JWT tokens to view Header and Payload content, visually check expiration and issuance times.
JWT Decoder
🚀 Quick Start
- Paste the complete JWT (three parts separated by ".")
- Auto-decode and display Header, Payload, and Signature
- View time claims (exp/nbf/iat) and status
📌 Common Scenarios
- API debugging: Quickly view token content to verify claims
- Expiration check: Inspect exp field to see if token is still valid
- Learning JWT: Understand Header/Payload structure and Base64URL encoding
- Environment comparison: Compare tokens across dev/test/prod environments
🧭 Usage Advice
- This tool only decodes—does not verify signatures; use backend validation in production
- Avoid pasting tokens with sensitive data on public devices
- Time fields are Unix timestamps (seconds); the tool auto-converts to local/UTC time
⚠️ Limitations & Compatibility
- Only Base64URL decoding—no signature verification
- Only standard 3-part JWT supported; JWE or custom formats not supported
- Nested JWTs (JWT inside payload) are not processed
🔒 Privacy & Security
- All processing happens in your browser—data never leaves your device
- If the token contains sensitive info, use in a private environment
❓ FAQ
Why does it say "Invalid format"?
Ensure the JWT has 3 parts (Header.Payload.Signature) separated by "."; check for extra spaces or line breaks
Shows "Expired" but server still accepts it?
Server may have grace period or clock skew; this tool uses local time and is for reference only