Validate & Debug JWT Tokens Instantly
Validate JWT tokens securely in your browser. Our free JWT validator helps you verify signatures, check expiration, and debug authentication issues.
Need to quickly inspect a JWT token?
Try our JWT Decoder for quick token inspection and payload viewing without advanced security checks.
Instantly validate and debug JWT (JSON Web Token) tokens online - completely free, with no registration required. Our advanced validator processes everything in your browser, ensuring your tokens and keys remain private and secure. Perfect for developers who need comprehensive token validation and debugging.
Whether you're verifying signatures, checking expiration dates, or debugging authentication issues, our instant JWT validator provides immediate results with support for all algorithms. No account needed, no data stored, and 100% secure browser-based processing.
JWT Validation Examples
Basic Token Validation:
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c
Validation Results:
Structure Check:
{
"valid": true,
"format": "Valid JWT format (header.payload.signature)",
"algorithm": "HS256",
"type": "JWT"
}Claims Validation:
{
"subject": "1234567890",
"name": "John Doe",
"issuedAt": "2018-01-18T01:30:22Z",
"status": "Valid token structure and claims"
}Advanced Token with Expiration:
eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCIsImtpZCI6ImF1dGgwIn0.eyJzdWIiOiJhdXRoMHw2MjM0NTYiLCJuYW1lIjoiQWxpY2UgU21pdGgiLCJlbWFpbCI6ImFsaWNlQGV4YW1wbGUuY29tIiwicm9sZXMiOlsiYWRtaW4iXSwiZXhwIjoxNzM1Njg5NjAwLCJpYXQiOjE3MDQwNjcyMDB9.signature
Validation Results:
Token Analysis:
{
"algorithm": "RS256",
"keyId": "auth0",
"tokenStatus": "Valid",
"expirationStatus": "Not expired",
"timeRemaining": "361 days"
}Note: RS256 (RSA-SHA256) is an asymmetric algorithm commonly used in production environments. The 'kid' claim helps identify which public key to use for verification.
Security Validation:
{
"claims": {
"subject": "auth0|623456",
"roles": [
"admin"
],
"issued": "2024-01-01T00:00:00Z",
"expires": "2025-01-01T00:00:00Z"
},
"securityChecks": {
"validStructure": true,
"validExpiration": true,
"validAlgorithm": true,
"validSignature": "Requires public key"
}
}Advanced Validation Features
Comprehensive Validation
Advanced token validation including structure verification, expiration checking, and signature validation with support for multiple algorithms (HS256, RS256, etc.).
Security Analysis
Detailed security checks including algorithm verification, claim validation, and expiration time analysis with clear feedback.
Privacy & Security
100% browser-based processing ensures your tokens and keys remain private. No server communication, no data storage, complete security.
Debug Assistant
Comprehensive error messages and validation feedback help quickly identify and resolve token issues during development.
How to Use
Paste your JWT token into the input field
View decoded header and payload data
Check validation results and expiration status
Review any error messages or validation feedback
Common Use Cases
Development
- Debug authentication issues
- Verify token contents
- Check token expiration
- Validate token format
- Inspect custom claims
Testing
- Test token generation
- Verify token signing
- Check token structure
- Validate token claims
- Debug token errors
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Frequently Asked Questions
What is a JWT token?
JWT (JSON Web Token) is a compact, URL-safe means of representing claims between two parties. It consists of three parts: header, payload, and signature, each encoded in base64 and separated by dots.
Is this tool secure?
Yes, all token processing happens directly in your browser. No tokens or keys are sent to our servers or stored anywhere. Your tokens remain completely private.
What validation is performed?
The tool checks token structure, format, expiration time, and signature if a secret key is provided. It also validates the token against JWT standards and common security practices.