Tiny Online Tools
Reading an .ics without importing it
An iCalendar file is easy to accept and hard to look at. A calendar application will import it, but importing is a commitment: the events land in your calendar, invitations may be answered on your behalf, and if the file was wrong you now have to undo it. This opens the file and shows you what is in it instead.
What is shown
The calendar's own properties — PRODID, VERSION, CALSCALE, METHOD and the X-WR-* extensions Google and Apple write — then every VEVENT, VTODO, VJOURNAL and VFREEBUSY in a sortable, searchable table.
Opening one shows everything the component carries: UID, SEQUENCE, DTSTAMP, CREATED, LAST-MODIFIED, CLASS, TRANSP, PRIORITY, CATEGORIES, URL, GEO and DESCRIPTION; the organizer and every attendee with their role, participation status, RSVP flag, calendar-user type and any delegation; every VALARM with its action and trigger; and the raw property lines with their line numbers, so nothing is hidden behind an interpretation.
Alarm triggers are resolved
A trigger is normally written as a duration — -PT15M — relative to the event's start, or to its end when the property carries RELATED=END. Both the raw value and the instant it resolves to are shown, because the raw value alone leaves you doing calendar arithmetic and the resolved instant alone hides which form the file actually used.
Time zones, and where the offsets came from
An .ics may name a real IANA zone (Europe/Vienna), or a name only its author knows (custom_America/New_York, or one of Microsoft's Romance Standard Time), and in the second case the file carries a VTIMEZONE describing the offsets itself — a recurrence rule per observance saying when the clocks change.
Offsets are taken from your browser's own IANA database when the TZID is a real zone name, and from the embedded VTIMEZONE when it is not. Which of the two applied is stated for every zone, along with each STANDARD and DAYLIGHT observance and its rule.
A time with neither a TZID nor a trailing Z is floating: it has no absolute instant at all until a zone is chosen. Those are flagged rather than quietly treated as UTC.
Attachments
An attachment stored inline as base64 can be downloaded. One stored as a URI is shown as text and is never fetched — this tool makes no network requests of any kind, and fetching it would tell whoever sent the file that you opened it.
Malformed files
Lines that are not valid content lines, and components never closed with an END, are reported with their line numbers rather than silently dropped.