ICS file validator
Check an .ics file structure: VCALENDAR, VEVENT and required fields.
🔒 100% client-side — no data sent
Validate an iCalendar .ics file and check its structure: VCALENDAR/VEVENT blocks, required fields (UID, DTSTART), compliant dates. Our online ICS validator flags missing or malformed fields. Everything is processed in your browser, with no data sent anywhere.
What is it for?
- ▸ Verify an .ics generated by your app before offering it for download.
- ▸ Debug an event that won't import into Google Calendar or Outlook.
- ▸ Check a calendar subscription feed (webcal) before publishing.
- ▸ Validate the structure of an invitation file before emailing it.
FAQ
Which fields are required in an .ics file?
A VCALENDAR requires VERSION and PRODID. Each VEVENT must contain at least a UID and a DTSTAMP, and usually a DTSTART. The validator flags any that are missing.
Why won't my .ics file import into Google Calendar?
Often due to a missing UID, an invalid DTSTART date format, or an improperly closed VEVENT block. The validator locates these structural problems.
What date format does .ics use?
The format looks like 20260724T140000Z (UTC) or with a timezone via TZID. A malformed date is a frequent cause of import failure.
Does my calendar stay private?
Yes. The .ics file is parsed locally in your browser. No event or personal detail is sent to a server.