Free calendar file tools

ICS Validator & Calendar Import Checker

Find missing IDs, invalid dates, broken structure and other common reasons an import can fail.

Calendar won’t import?Start with the import checklist

Your file

Preview

Waiting for a file

Know what you’re importing.

See event dates, check time zones, and spot warnings before opening your calendar app.

Your calendar account is never connected.

A structural check cannot guarantee that Google, Apple or Outlook will accept a file. Read warnings before importing a copy into a test calendar.

How to use this tool

Open the ICS file that is giving you trouble.
Read the errors and warnings, including the file-size check.
Use the matching tool or guide to fix the underlying issue.

Before you export

Does passing mean my file is fully RFC compliant?＋

No. This checks common event structure, dates, required IDs, duplicate identities and timezone definitions. It is not a complete RFC certification or an actual calendar import test.

Can you repair everything automatically?＋

No. Missing time zones, conflicting revisions and ambiguous dates need your decision. The checker explains them instead of guessing.

Uses the iCalendar standard. Keep the original file and test the output in your receiving calendar app.