Pure Frontend · Header/Payload Parsing · Standard Claims · Expiration Check
Zero Dependencies · Works OfflineWhat Can the JWT Claims Extractor Do?
The JWT Claims Extractor is a pure frontend online tool for parsing JWT Token Header and Payload, extracting all Claims. Supports RFC 7519 standard Claims (iss, sub, aud, exp, nbf, iat, jti) and custom Claims, with automatic expiration detection and descriptions for each standard Claim. All decoding happens locally in the browser.
Core Features
- Header Parsing: Display algorithm (alg) and type (typ)
- Claims Extraction: Parse all Payload Claims with descriptions
- Expiration Check: Auto-detect exp/nbf, show validity and remaining time
- Timestamp Conversion: Convert Unix timestamps to readable dates
- One-Click Copy: Copy Header or Claims JSON data
How to Use
Step 1: Paste your JWT Token in the input area.
Step 2: Click "Parse" or press Ctrl+Enter.
Step 3: Review Header, Claims, and Token status.
Step 4: Copy the Claims data you need.
Use Cases
API Debugging
Developers check Token Claims to verify identity and permissions when debugging OAuth2/OIDC flows.
Token Troubleshooting
Quickly check exp, aud and other key fields when troubleshooting expired or mismatched tokens.
Security Audit
Security teams review signing algorithms, expiration policies, and Claims for security compliance.
Learning
Beginners understand JWT structure and Claims by parsing real tokens.
Extended Knowledge
JWT (JSON Web Token) consists of three parts: Header.Payload.Signature, separated by dots. Header contains metadata (algorithm, type), Payload contains Claims, and Signature verifies integrity. RFC 7519 defines 7 standard Claims: iss (issuer), sub (subject), aud (audience), exp (expiration), nbf (not before), iat (issued at), jti (JWT ID). JWT Payload is only Base64Url-encoded, not encrypted, so never store sensitive data in Claims.
FAQ
What are JWT Claims?
JWT Claims are statements in the Payload such as iss (issuer), sub (subject), aud (audience), exp (expiration), iat (issued at), and custom fields.
Does this tool verify signatures?
No. This tool only decodes Header and Payload. Signature verification requires secret keys and is not safe in the browser.
Is data uploaded to a server?
No. All decoding happens locally. Token data never leaves your device.
Are JWE tokens supported?
Currently only JWS (signed JWT) is supported. JWE (encrypted JWT) is not yet available.
How to check token expiration?
After parsing, the exp Claim is automatically compared with current time to show status and remaining time.
What standard Claims are supported?
All RFC 7519 standard Claims: iss, sub, aud, exp, nbf, iat, jti, plus OpenID Connect extensions.