An .ics file is a small calendar file that someone sent you or that you downloaded from a website. Opening it should add the event to your calendar. This guide shows how to do that on Windows, Mac, iPhone and Android, how to look inside the file, and what to do when it will not open.

Disclosure. I'm the maker of Yotei, an app that adds an event to your calendar straight from your screen, with no file in between. It is mentioned once, near the end. The steps below work without it.

The short answer

  • Windows: double-click the file. If nothing happens, right-click it, choose Open with and pick your calendar program, or import it into Google Calendar or Outlook.com in your browser.
  • Mac: double-click the file. Calendar opens and asks which calendar to add the event to.
  • iPhone: tap the file in Mail, Messages or Files, then tap Add All or Add to Calendar.
  • Android: open the file from your notifications or the Files app and choose your calendar app, usually Google Calendar.
  • Any device: upload the file in the web version of Google Calendar (Settings, Import & Export) or Outlook.com (Add calendar, Upload from file).

Open an .ics file on Windows

Double-click the file. If a calendar program such as Outlook is installed and set as the default for .ics files, it opens the event and you save it. If Windows asks which app to use, pick your calendar app and tick the box to use it every time.

If you do not have a calendar program, use your browser. In Google Calendar, open Settings, then Import & Export, choose the file and press Import. In Outlook.com or Outlook on the web, choose Add calendar, then Upload from file. Both work without installing anything.

If the file ends in .ics.txt, Windows is hiding the real extension. Turn on File name extensions in File Explorer's View menu and rename the file so it ends in .ics.

Open an .ics file on a Mac

Double-click the file. Calendar opens and asks which calendar to add the events to. You can also use File, then Import, in Calendar, or drag the file into the Calendar window.

Open an .ics file on an iPhone or iPad

Tap the file wherever you received it: Mail, Messages, WhatsApp or the Files app. A sheet shows the events with an Add All button, and you choose the calendar to save them in. If you downloaded the file in Safari, open it from the Downloads folder in Files.

Open an .ics file on Android

Open the downloaded file from the notification or from the Files app. Android offers the apps that can read it. Choose Google Calendar or your own calendar app and confirm the import. If no app is offered, import the file in Google Calendar in a browser instead, as described above, and the events appear on your phone after it syncs.

Look inside the file

An .ics file is plain text, so Notepad or TextEdit can show it. You will see lines like these:

BEGIN:VCALENDAR
VERSION:2.0
BEGIN:VEVENT
UID:5b1d2c0e-7a3f@example.com
DTSTART:20261117T090000Z
DTEND:20261117T100000Z
SUMMARY:Meeting
LOCATION:Room 4
END:VEVENT
END:VCALENDAR

SUMMARY is the title, DTSTART and DTEND are the start and end, and a time that ends in Z is in UTC. One file can hold many events, each between BEGIN:VEVENT and END:VEVENT.

If the file will not open

  • Check the extension. It must end in .ics. A file called invite.ics.txt or invite.ics.zip is something else.
  • Download it first. Opening an attachment inside a mail preview sometimes does nothing. Save the file and open it from your downloads.
  • Try another calendar. A file that Outlook rejects often imports into Google Calendar, and the other way round.
  • Check the file for errors. A missing UID, a wrong date format or an event that ends before it starts stops an import. The free ICS validator lists what is wrong, with line numbers.
  • Make a new one. If you have the details, the ICS file generator makes a clean file in a minute.

Import or subscribe?

Opening an .ics file copies its events into your calendar once. If the sender keeps changing the schedule, ask for a subscription link instead (it often starts with webcal://). A subscribed calendar updates by itself, and an imported file does not.

Skip the file

If you only have the event as text, Text to ICS turns it into a file, and the text to calendar event page opens it straight in Google Calendar or Outlook. If the event is in a screenshot, a chat or a PDF, Yotei reads it from your screen: press a shortcut, drag a box around it and confirm. There is a free plan with 10 automatic readings a month. See pricing.

FAQ

How do I open an .ics file?

Double-click it on a computer, or tap it on a phone, and choose your calendar app. In a browser you can import it through Settings in Google Calendar or Add calendar in Outlook.com.

Why does my .ics file open in a text editor?

Your computer has no calendar program set for .ics files. Use Open with and choose one, or import the file in a web calendar.

Is an .ics file safe to open?

The file only contains text about events, so it cannot run code. Be careful with the links inside the event description, as you would with any link in an email.

Can I open an .ics file without a calendar app?

Yes. A text editor shows its contents, and the free calendars in a browser import it without an app.

Does opening the file twice add the event twice?

It can. Some apps recognise the same event by its UID and update it, others add a second copy. Delete the extra one.