JWT Decoder
Decode and inspect JWT tokens with payload visualization.
Important Notes:
- This tool only decodes the JWT, it does not verify the signature
- All processing happens in your browser - your tokens are not sent anywhere
- Never paste production tokens on untrusted sites
- Common claims: iss (issuer), sub (subject), exp (expiration), iat (issued at)
About JWT Tokens
JSON Web Tokens (JWT) are an open standard (RFC 7519) for securely transmitting information between parties as a JSON object. JWTs are commonly used for authentication and information exchange in modern web applications.
Features
- Decode JWT tokens instantly
- View header, payload, and signature separately
- Beautiful syntax highlighting for JSON data
- Inspect token claims and metadata
- Copy decoded sections to clipboard
- 100% client-side - your tokens never leave your browser
- Privacy-focused and secure
JWT Structure
A JWT consists of three parts separated by dots (.):
- Header: Contains token type and signing algorithm
- Payload: Contains the claims (data)
- Signature: Ensures the token hasn't been altered
Common Use Cases
- Debugging authentication issues in web applications
- Inspecting token claims and expiration times
- Understanding JWT structure for development
- Verifying token contents before API calls
- Learning about JWT implementation
How to Use
- Paste your JWT token into the input field
- The tool automatically decodes and displays the header and payload
- Review the decoded information with syntax highlighting
- Copy specific sections as needed
Note: This tool only decodes tokens. It does not verify signatures. Never paste sensitive or production tokens into any online tool.