JWT Expiration (exp / iat) Timestamp & Payload Checker
Convert Unix epoch `exp`, `iat`, and `nbf` claims into human-readable timestamps and verify whether an authentication token is still active.
Step-by-Step Client-Side Workflow
- Input JWT String: Drop your access or ID token into the local parser.
- Inspect `exp` & `iat` Badges: See immediately whether the token is Active or Expired alongside converted date-time strings.
- Copy Clean Payload JSON: Copy the decoded claims JSON for unit tests or API documentation.
Why Use VaultTools Zero-Upload Architecture
- Zero Production Token Leaks: Safely inspect live bearer tokens, OAuth ID tokens, and session cookies without violating SOC2 or ISO 27001 security policies.
- Instant Expiration Diagnostics: Immediately see whether a token is active or expired with live countdowns and formatted claim breakdowns.
- Works in Air-Gapped Environments: Debug authentication flows on locked-down corporate VPNs or offline development machines.
Frequently Asked Questions
What do the `exp`, `iat`, and `nbf` fields in a JWT mean?
`exp` (Expiration Time) is the Unix timestamp after which the token must be rejected, `iat` (Issued At) records when the token was created, and `nbf` (Not Before) specifies when the token becomes valid.
Is it safe to paste a live production JWT into VaultTools?
Yes. VaultTools runs 100% client-side in your browser RAM with zero network requests. You can even disconnect from the internet before pasting your JWT to verify that no data leaves your device.
Can anyone read the payload of a JWT without the secret key?
Yes! Standard JWTs (JWS) are Base64Url-encoded, not encrypted. Anyone who intercepts a JWT can read its header and payload claims—the secret key is only used to verify that the signature was not tampered with.
What do the exp, iat, and sub claims mean in a JWT?
"exp" (Expiration Time) defines when the token becomes invalid, "iat" (Issued At) records when the token was minted, and "sub" (Subject) identifies the user or principal the token belongs to.