JWT Decoder
Decode and inspect JSON Web Tokens (JWT). View header, payload, and signature with formatted output and expiration checking.
Common JWT Claims
iss - Issuer
sub - Subject
aud - Audience
exp - Expiration Time
nbf - Not Before
iat - Issued At
jti - JWT ID
This decoder runs entirely in your browser. Your JWT is never sent to any server.
How This Tool Was Built
This tool was created entirely by AI. Here's the exact prompt used to generate it:
Prompt Used
Create a JWT Decoder tool with these features: 1. Input area for pasting JWT tokens 2. Decode and display: - Header section (algorithm, type) - Payload section (all claims) - Signature (raw base64) 3. Format timestamps (iat, exp, nbf) as human-readable dates 4. Show EXPIRED badge if token is expired 5. Color-coded sections (red header, purple payload, cyan signature) 6. Copy buttons for each section 7. Example JWT button 8. Common claims reference 9. Use base64url decoding (handle URL-safe base64) 10. Clear error messages for invalid tokens Make it developer-friendly with orange as the accent color. Emphasize this is decode-only (no signature verification without secret).
Claude AI Model
7,200 Tokens Used
AI-Generated Code Origin