JWT Expiration Checker
Check a JWT's expiry time and whether it has expired.
Output will appear here...About JWT Expiration Checker
The JWT Expiration Checker reads a token's exp claim, converts the Unix timestamp to a readable date, and tells you whether the token is still valid or already expired. It's the fastest way to rule out expiry when debugging a 401 during authentication. Everything is decoded in your browser, so you can safely check production tokens. For the full header and payload, use the JWT Decoder, and to read auth headers the Bearer Token Parser.
How to Use
- 1Open JWT Expiration Checker and paste or type your data into the input area.
- 2Adjust any available options to match the result you want.
- 3Your output is generated instantly — no button-clicking required for most tools.
- 4Use the Copy or Download button to save your result.
Common Use Cases
- Inspecting JWT claims while debugging authentication
- Converting cURL commands into fetch or Axios code
- Building and parsing query strings and tracking URLs
- Looking up HTTP status codes during API development
Frequently Asked Questions
How is expiry determined?
The checker reads the token's exp claim, a Unix timestamp, and compares it to the current time. If exp is in the past the token is expired; it also shows iat and nbf when present.
Does checking expiry validate the token?
No. It only reads the expiry claim. It does not verify the signature, which requires the secret or key and should be done server-side. Use it purely to diagnose expiry.
Is JWT Expiration Checker free to use?
Yes. JWT Expiration Checker is completely free with no sign-up, no subscription, and no usage limits. Every tool on CodeUtilityKit is free forever.
Is my data safe when I use JWT Expiration Checker?
Absolutely. JWT Expiration Checker runs entirely in your browser. Your input is processed locally with JavaScript and is never sent to, stored on, or logged by any server — so it is safe even for private or sensitive data.
Features
- Run JWT Expiration Checker instantly, right in your browser
- 100% private — your data never leaves your device
- Copy the result to your clipboard in one click
- Free and unlimited with no account or sign-up
- Clear, friendly error messages when something is wrong
- Works on desktop and mobile, even offline after first load
Related tools: JWT Decoder, Bearer Token Parser.