What is an ICS file?
An ICS file is a plain-text calendar file that follows the iCalendar standard, RFC 5545. Open one in a text editor and the event is written out line by line: what it is called, when it starts and ends, which timezone those times belong to, where it happens. A calendar app reads those lines and rebuilds the event.
The standard has been public since 1998, which is why a single file works in Apple Calendar, Outlook, Google Calendar, Thunderbird and the calendar built into most phones. That is the practical difference between a file and a calendar link: a link only helps people who use that one provider, while a file works for whoever you send it to. It is the same format your email client uses when it sends a meeting invitation.
BEGIN:VEVENTUID:[email protected]DTSTART;TZID=America/New_York:20260814T090000DTEND;TZID=America/New_York:20260814T103000SUMMARY:Q3 Product ReviewLOCATION:Studio B, 44 Wall StreetDESCRIPTION:Roadmap walkthrough and demos.END:VEVENTThe lines that matter
- SUMMARY
- The event title, and the only thing most people see on the calendar grid.
- DTSTART / DTEND
- Start and end, either as a timezone-anchored moment or a bare date.
- LOCATION
- An address, a room name, or a meeting URL.
- DESCRIPTION
- Agenda, notes, and links. Long values are wrapped across lines.
- UID
- A unique id. Re-sending a file with the same UID updates the event instead of duplicating it.
How to create an ICS file
Enter the event details
A title and a start and end time are all the file needs. Location and description are optional, and the description keeps its formatting and links when it reaches the calendar.
Choose a timezone, or mark it all-day
The timezone you pick is the one your times are interpreted in, so someone opening the file elsewhere sees the correct local hour. Turn on All Day Event and the timezone control switches off: the event is stored as a plain date and stays on that date everywhere.
Download and send it
Download ICS File writes the file in your browser and saves it straight to your device. Attach it to an invitation email, drop it into a chat, or link to it from a page.
Opening a .ics file in your calendar
Every app below reads the same file. Only the way you hand it over differs.
- Apple Calendar
- Double-click the file on macOS and Calendar asks which calendar to add it to. On iPhone or iPad, open the attachment and tap Add All.
- Google Calendar
- Google will not open a downloaded file directly. Go to Settings, then Import & export, choose the file, pick the calendar, and select Import.
- Outlook (desktop)
- Double-clicking opens the event, and Save & Close adds it. To import several at once, use File, Open & Export, Import/Export, then Import an iCalendar (.ics) file.
- Outlook on the web and Office 365
- In the calendar sidebar choose Add calendar, then Upload from file.
- Mozilla Thunderbird
- Use File, Open, Calendar File, then select the .ics file.
- Android
- Most Android calendars are backed by a Google account, so import through Google Calendar on the web and the event syncs down to the phone.
Frequently asked questions
What is an ICS file?
An ICS file (.ics) is a plain-text calendar file that follows the iCalendar standard, RFC 5545. It stores an event as a set of labelled lines - title, start and end time, timezone, location, description. Any calendar app that supports the standard can read those lines and recreate the event.
How do I create an ICS file?
Fill in the event title, date, time, location and description in the generator at the top of this page, then click Download ICS File. The file is written in your browser and saved to your device. No account, no software, no upload.
Is this ICS file generator free?
Yes. There is no limit on how many .ics files you create, no watermark, and no signup.
What is the difference between .ics, .ical and iCalendar?
They refer to the same thing. iCalendar is the name of the format, .ics is its standard file extension, and .ical is an older extension you still see occasionally. A calendar app that opens one will open the others.
Can one ICS file hold more than one event?
The format allows it - a single file can contain many VEVENT blocks, which is how calendar exports work. This generator creates one event per file, so for several events you would download one file for each.
My event appears at the wrong time. What happened?
Almost always a timezone mismatch. The times you type are interpreted in the timezone selected in the form rather than the one your computer is set to, so check that the selector matches the timezone you meant. If only the date matters, use All Day Event and the event will not move between timezones.
Can I email an ICS file to attendees?
Yes, and it is the most reliable way to share an event, because recipients can add it to whatever calendar app they already use. Most email clients recognise the attachment and offer to add the event directly.
Do you store the events I create?
No. The file is assembled entirely in your browser, so the event details never reach our servers.
If you need a link instead of a file
A link drops the event straight into one provider without a download. Use the Google Calendar link generator or the Outlook calendar link generator, or head back to the generator.