ISO 8601 Validator
Paste an ISO 8601 date to check whether it is valid — complete with the reason if it is invalid and a component breakdown if it is valid. Everything is processed on your device.
Everything runs in your browser. Your data is never sent to our servers.
Example
Example Input
2026-13-01
Example Output
✗ INVALID — month 13 outside 1–12
How to Use
- 1Paste the an ISO 8601 date you want to check into the input box.
- 2If the tool offers extra options (e.g. dialect, flags, or variant), set them as needed.
- 3Click Validate (or press Ctrl+Enter).
- 4Read the result badge — VALID, INVALID, or VALID with a warning — along with the details and the list of issues, if any.
About ISO 8601 Validator
ISO 8601 Validator checks whether a string follows the ISO 8601 date/time format (YYYY-MM-DD, optionally followed by THH:MM:SS and a time zone). Beyond the pattern, it also validates value ranges: month 1–12, day per month (including leap years), hour 0–23, and minute 0–59.
ISO 8601 is the standard date format for APIs and databases. Validation confirms the date is actually sensible, not just pattern-matching.
FAQ
Is my data sent to a server?
No. All validation runs in your browser with JavaScript. Nothing is uploaded, logged, or stored on our servers — safe for sensitive data.
How is this validator different from a parser or formatter?
A validator answers one question: is this input correct/valid? It returns a valid/invalid badge with the reason. A parser breaks input into its components, and a formatter tidies its layout. Use a validator when you just need to confirm something is sound before using it.