Title, location, date and time, time zone, repeat, invitees, alerts, and notes — then download the .ics file or open it straight in your calendar. You can also paste a schedule or attach a document or photo to make several events at once.
What is an .ics file?
An .ics file is one calendar event — or several — written as plain text in the iCalendar format, standardised as RFC 5545 in 2009 and unchanged since. The event sits between BEGIN:VEVENT and END:VEVENT, where SUMMARY is the title, DTSTART and DTEND are the times, LOCATION and DESCRIPTION are what they sound like, and UID is the identifier a calendar uses to tell an update from a new event. Apple Calendar, Google Calendar, Outlook, and Thunderbird all read it, which is why an invitation emailed between two companies lands correctly in both. ICS Maker builds one from a form and shows the exact file text beside it as you type.
What is inside one
Open an .ics file in a text editor and it reads as a short list of properties. The event itself sits between BEGIN:VEVENT and END:VEVENT: SUMMARY is the title, DTSTART and DTEND are the times, LOCATION and DESCRIPTION are what you would expect, and UID is the identifier a calendar uses to tell an update from a new event. The format is RFC 5545, published in 2009 and unchanged since — which is why a file written today opens in software written a decade ago.
The preview beside the form is the real file, updating as you type. Nothing is hidden from you and nothing is added: what you read there is byte for byte what downloads.
How to open one
- macOS and iOS
- Double-click or tap the file; Calendar offers to add the event.
- Google Calendar
- Settings → Import & export → Import, then pick the file and the calendar it should land in.
- Outlook
- File → Open & Export → Import/Export → Import an iCalendar (.ics) file, or just double-click it in Windows.
- Android
- Most Android calendars import through Google Calendar on the web rather than from the phone — mail yourself the file and open it on a desktop.
Questions
- What does ICS stand for?
- It is simply the file extension for iCalendar data — short for "iCalendar Stream". The format itself is defined by RFC 5545, and the same content is sometimes served with the media type text/calendar.
- Is .ics the same as iCal?
- Nearly. iCal was Apple’s calendar app, now just called Calendar, and people borrowed the name for the format it read. The format’s real name is iCalendar and its files end in .ics.
- Can one .ics file hold several events?
- Yes. An .ics file can contain multiple VEVENT blocks. In ICS Maker, collect events from the form, a pasted schedule or an attached file. Review and correct them, then download them together as one .ics file. Importing copies the events; it does not create a calendar subscription.
- Can I edit an .ics file by hand?
- You can, and it is a reasonable way to fix a typo — it is plain text with one property per line. Keep the line endings as CRLF and keep long lines folded, or strict parsers will complain.