Free tool
ICS file viewer & validator
Peek inside any .ics file before you import it: events, recurrence rules, metadata — and the format problems that make calendar apps choke. Everything stays in your browser.
Your .ics file
Drop an .ics file here
What's inside
Drop a file or paste ICS text to see its contents.
Validation
Events
Importing .ics files by hand, again and again?
An import is a one-time snapshot — it goes stale the moment the source changes. SyncThemCalendars keeps Google, Outlook and Apple iCloud calendars continuously in sync instead.
Start syncing freeFrequently asked questions
What is an .ics file?
It's the universal calendar format (iCalendar, RFC 5545) — a plain-text file describing events, their times, time zones and recurrence rules. Every calendar app can read it: Google Calendar, Outlook, Apple Calendar, and the invitation attachments in your inbox are all .ics.
Is my file uploaded to your servers?
No. The file is parsed entirely in your browser with JavaScript — nothing is sent to our servers, stored or logged. You can even use the tool offline once the page is loaded.
Why do my events land at the wrong time after an import?
Almost always a time-zone problem. Common culprits this validator flags: TZID values that aren't IANA names (Windows zone names like "Romance Standard Time"), or floating times (no zone, no Z suffix) that each app anchors differently.
What are UID and RECURRENCE-ID?
UID is an event's identity: apps use it to know whether an incoming event updates an existing one or creates a new one. RECURRENCE-ID marks an exception to a recurring series — "the occurrence of March 4th, moved to 3pm". An exception whose parent series is missing is an orphan, and many apps silently drop it.