JWT Decoder
Decode JSON Web Tokens to inspect header, payload, and signature.
✅ 100% Free
🔒 Privacy First
⚡ Instant Results
What is a JWT Decoder?
A JWT is a compact, URL-safe token with three Base64URL-encoded parts: header, payload, and signature.
How to Use This JWT Decoder
- Paste your JWT.
- See the decoded header and payload.
How It Works
The tool splits the token on dots and Base64URL-decodes each part.
Example Calculation
eyJhbGciOiJIUzI1NiJ9.eyJzdWIiOiIxMjMifQ.signature decodes to {"alg":"HS256"} and {"sub":"123"}.
Frequently Asked Questions
Does this verify the signature?
No. It decodes the token only. Signature verification requires the secret key.
Privacy & Data Processing
All processing happens in your browser. Tokens are never uploaded.
Last updated: 2026-10-01