Split ICS File by Category
Split a large ICS calendar file into multiple files by event category. Automatically detects CATEGORIES and creates separate ICS files. Free online splitter tool.
ICS Splitter – Split a Calendar File by Event Category
A single ICS file can contain hundreds or thousands of events spanning multiple categories such as work meetings, personal appointments, holidays, birthdays, and project milestones. When you need to separate these events into individual calendars, manually sorting them is tedious and error-prone. This tool reads the CATEGORIES property of each event in your ICS file and splits the events into separate ICS files, one per category. The result is a set of focused calendar files that you can import independently into Google Calendar, Apple Calendar, Microsoft Outlook, or any other calendar application, giving you granular control over which events appear where.
How Category-Based Splitting Works
The tool parses every VEVENT component in your ICS file and examines the CATEGORIES property. Events assigned to the same category are grouped together and written to a dedicated ICS file named after that category. Events with multiple categories appear in each corresponding output file so that no data is lost. Events without a CATEGORIES property are collected into a separate "uncategorized" file. Each output file includes the necessary VCALENDAR wrapper, VERSION, PRODID, and any VTIMEZONE definitions referenced by the events it contains. The output files are valid, self-contained ICS files ready for import.
Use Cases for Splitting Calendars by Category
A common scenario is separating a mixed work-and-personal calendar after leaving a job. You may want to keep personal events in your private calendar and archive work events separately. Teachers who maintain a single calendar with categories for different classes can split the file at the end of a semester to create individual archives for each course. Conference organizers who tag sessions with track names like "Keynote," "Workshop," and "Networking" can produce per-track calendars for attendees. IT administrators migrating calendar data can split a large export by department before distributing category-specific files to each team.
Working with Events That Have Multiple Categories
The iCalendar specification allows an event to belong to more than one category. For example, a team lunch might be categorized as both "Social" and "Team Building." When this tool encounters multi-category events, it includes the event in every relevant output file by default. This ensures that each split calendar is complete and that filtering by a single category does not cause you to miss events that also belong to another category. If you prefer strict partitioning where each event appears in only one file, you can configure the tool to use only the first category listed in the CATEGORIES property.
Importing Split Calendars into Different Applications
After splitting, you can import each category file into a separate calendar within your application. In Google Calendar, create a new calendar for each category via Settings, then import the corresponding file into it. In Apple Calendar, you can drag the ICS file onto a specific calendar in the sidebar or use File, then Import and choose the target calendar. In Microsoft Outlook, use the Import wizard and select the destination calendar folder. This approach lets you toggle visibility for each category independently and apply different color codes, which is more flexible than having all events in a single calendar with mixed formatting.
Frequently Asked Questions
What happens to events that do not have a category?
Events without a CATEGORIES property are placed into a separate "uncategorized" output file. This ensures that every event from the original file is accounted for in the split output, even if it was never assigned a category.
Can an event appear in multiple output files?
Yes. If an event has multiple categories, it will appear in the output file for each category by default. You can change this behavior to assign each event to only its first category if you prefer strict separation.
Does splitting preserve recurring events?
Yes. Recurring events, including their RRULE definitions and any EXDATE exceptions, are preserved intact in the output files. The recurrence information is not altered during the split process.
How are the output files named?
Each output file is named after its category with a .ics extension. Special characters in category names are replaced with hyphens to ensure the filename is valid across all operating systems. For example, a category named "Work/Meetings" becomes "Work-Meetings.ics."
Can I split by a property other than CATEGORIES?
This tool specifically splits by the CATEGORIES property, which is the standard way events are classified in the iCalendar format. If your events use a custom property for classification, consider re-mapping that property to CATEGORIES before splitting.
Is there a limit on how many categories the tool can handle?
There is no practical limit. The tool creates one output file per unique category found in your ICS file. Whether you have 3 categories or 30, each one gets its own clean ICS file.
Will the split files work with Google Calendar and Outlook?
Yes. Each output file is a valid ICS file conforming to RFC 5545. They can be imported into Google Calendar, Microsoft Outlook, Apple Calendar, Thunderbird, and any other application that supports the iCalendar standard.