Question 1

How do I validate an ICS file?

Accepted Answer

Paste the .ics text or upload the file above. The validator checks the calendar against the iCalendar standard (RFC 5545) and reports any errors and warnings: a missing or unparseable DTSTART, an end time before the start, a missing UID, an absent VERSION or PRODID, and more. It also shows a parsed summary so you can confirm the events came through.

Question 2

What is the difference between an error and a warning?

Accepted Answer

Errors are problems that usually cause a calendar app to drop the event or reject the import, for example a missing start date or an end before the start. Warnings are non-fatal: the file should still import, but it deviates from the standard (such as a missing UID or PRODID) and could behave inconsistently across apps.

Question 3

Why won't my ICS file import into Google Calendar or Outlook?

Accepted Answer

The most common causes are a malformed DTSTART/DTEND, missing required properties, or incorrect line folding. Run the file through this validator: the errors list points at the exact event and property to fix. Once there are no errors, the file should import cleanly.

Question 4

Is the ICS validator free and private?

Accepted Answer

Yes. It is free, needs no sign-up, and validates the file entirely in your browser. Nothing is uploaded to a server.

Free ICS Validator

Paste or upload the .ics file to validate

What the validator checks

More free calendar tools

Frequently asked questions

File broken beyond repair?