JWT Decoder - Decode & Inspect JSON Web Tokens
Decode any JWT to view its header, payload claims, and signature. Inspect expiration times, issuers, and custom claims for debugging authentication flows.
Understanding This Tool
What It Does
Decode and analyze JWT (JSON Web Token) structure including header, payload, and signature. This tool shows you what data is contained in a JWT without needing to validate the signature.
Understanding the Results
- Header: Token type and signing algorithm information
- Payload: The claims/data contained in the token
- Signature: The cryptographic signature (not verified)
- Claims: Individual pieces of data in the token
- Expiration: When the token expires (if set)
Common Use Cases
- Token Inspection: See what data a JWT contains
- Debugging: Troubleshoot authentication issues
- API Testing: Analyze tokens returned by APIs
- Security Review: Verify tokens don't contain sensitive data
- Claim Validation: Check token expiration and other claims
Pro Tips & Best Practices
- Three Parts: JWTs consist of three Base64-encoded parts separated by dots
- No Encryption: JWT payload is encoded but not encrypted; don't store secrets
- Signature Validation: This tool doesn't verify the signature; use server-side validation
Last reviewed:
How this tool works: This tool runs in your browser and on our server in real time. Depending on the tool, results are computed directly from the input you provide or retrieved from live, authoritative data sources at the moment you run a lookup. We do not sell your data, and your lookups are kept private — any history shown here is stored only on your device.