JWT Decoder – Decode & Inspect JWT Tokens Free Online
Decode and inspect JWT (JSON Web Token) tokens. View header, payload, and signature. Free JWT decoder - no upload required.
Frequently Asked Questions
A JSON Web Token (JWT) is a compact, URL-safe token format used to represent claims between two parties. It consists of three Base64URL-encoded parts: a header, a payload, and a signature, separated by dots.
No. Signature verification requires the secret key or public key used to sign the token, which is not available client-side. This tool only decodes and displays the header and payload claims.
The token is decoded entirely in your browser and never sent to any server. However, JWTs may contain sensitive claims — avoid pasting production tokens in shared or untrusted environments.
These are standard JWT claims: iat (issued at) is the Unix timestamp when the token was created, exp (expiration) is when it expires, and nbf (not before) is the earliest time the token is valid. All are Unix timestamps (seconds since epoch).
If the payload contains an exp claim and the current time is past that timestamp, the token is considered expired. This is a client-side check based on your device's clock.
What is JWT Decoder?
A JWT (JSON Web Token) is a compact, URL-safe token format used for authentication and information exchange in web applications. It consists of three parts: a header (algorithm and token type), a payload (claims/data), and a signature. Our JWT Decoder parses and displays all three parts in a readable format, making it easy to inspect token contents during development and debugging. The expiry time (exp claim) is shown in human-readable format.
How to Use JWT Decoder
- 1Paste your JWT token into the input field.
- 2The decoder automatically splits and decodes the header and payload.
- 3Review the decoded JSON for each section.
- 4Check the expiry time displayed in human-readable format.
Key Features
- ✓Decodes JWT header, payload, and signature
- ✓Displays expiry time (exp) in human-readable format
- ✓Syntax-highlighted JSON output
- ✓Runs entirely in your browser
- ✓No data sent to any server
Benefits
- →Debug authentication issues in web applications
- →Inspect token claims during development
- →Verify token structure and expiry
- →Understand JWT format and contents
Why Use Irreva for JWT Decoder?
Frequently Asked Questions
What is a JWT?
JWT (JSON Web Token) is an open standard (RFC 7519) for securely transmitting information between parties as a JSON object. It is commonly used for authentication in web APIs.
Can this tool verify the JWT signature?
No. Signature verification requires the secret key or public key used to sign the token. This tool only decodes the header and payload, which are Base64-encoded but not encrypted.
Is it safe to paste my JWT here?
The decoding happens entirely in your browser - the JWT string is parsed by JavaScript running in your tab and is never transmitted to any server. That said, as a general security habit, avoid pasting long-lived production tokens containing sensitive claims into any web tool.
What is the exp claim?
The exp (expiration time) claim is a Unix timestamp indicating when the token expires. The tool converts this to a human-readable date and time.
Rate JWT Decoder
How useful was this tool?