Original reference guides · Reviewed 8 October 2026

Valid-looking text: escaping, folding, and UTF-8

Start here when: descriptions disappear, accented text breaks, or a file imports only partly.

ICS is structured text. TEXT values escape backslashes, commas, semicolons, and embedded newlines. Physical lines use CRLF. Keep each physical line to no more than 75 octets (bytes), excluding CRLF, by folding between characters with CRLF plus a space or tab. Count the continuation whitespace in that line’s byte length; avoid splitting a UTF-8 character. UTF-8 is the default character set. RFC 5545, content lines and TEXT escaping.

A tiny text test

The download text-and-folding.ics contains a fictional “Café planning, sample” event. Its description should display a comma, a semicolon, a backslash, and a second description line. Compare the rendered text with these intended contents:

Bring paper, pencils; and a folder named Sample\Notes.
This second line is part of the description.

Use a plain-text editor to inspect the file. A screenshot cannot reveal whether the physical bytes contain a newline, a literal backslash followed by n, or a missing continuation space. Similarly, an editor's soft wrapping does not necessarily insert any actual line break.

Isolate the failure

Start with the smallest synthetic file that exhibits the problem. Compare its first and last lines with the untouched download. Then inspect the property immediately before the missing text. If a long description was split during copying, its continuation may have become a separate invalid line. If accented characters changed, preserve the original bytes before trying another save encoding.

Microsoft documents that listed Outlook versions tolerate several line-ending variants and long physical lines on import. That tolerance is useful context when a file works in Outlook but fails elsewhere; it is not evidence that the producer wrote portable ICS. Keep exports conservative rather than depending on a forgiving reader. Microsoft content-line notes.

Google's troubleshooting page currently specifies a 1 MB import-file limit. For a large export, reduce the date range at the source where possible. When splitting manually, preserve complete calendar structure and related recurrence components. A smaller broken file is still broken. Google import troubleshooting.

Final check: import success is only the first checkpoint. Verify the visible title, exact dates, duration, special characters, and intended recurrence behavior before trusting a real migration.