Generate a QR Code for Calendar Events

QR Codes for Calendar Events

Event QR codes encode calendar event data so users can add an event to their calendar by scanning. There are two main approaches: encoding raw iCalendar data or encoding a Google Calendar URL.

Approach 1: iCalendar (ICS) Format

The iCalendar format is universally supported:

BEGIN:VCALENDAR
VERSION:2.0
BEGIN:VEVENT
DTSTART:20250415T140000Z
DTEND:20250415T160000Z
SUMMARY:DevConf 2025 Workshop
DESCRIPTION:Hands-on QR code workshop
LOCATION:Room 4B, Convention Center
END:VEVENT
END:VCALENDAR

Approach 2: Google Calendar URL

A Google Calendar link provides a better user experience for Google Calendar users:

https://calendar.google.com/calendar/render?action=TEMPLATE&text=DevConf+Workshop&dates=20250415T140000Z/20250415T160000Z&details=Hands-on+QR+code+workshop&location=Room+4B

Date and Time Formatting

iCalendar uses the YYYYMMDDTHHMMSS format:

Format	Meaning
20250415T140000Z	UTC time
20250415T140000	Local time (floating)
TZID=America/New_York:20250415T100000	Timezone-specific

Always specify the timezone explicitly to avoid confusion for attendees in different time zones.

All-Day Events

For all-day events, use the date-only format:

DTSTART;VALUE=DATE:20250415
DTEND;VALUE=DATE:20250416

Note: The end date is exclusive, so a single-day event on April 15 has an end date of April 16.

Keeping the QR Code Compact

iCalendar data can grow quickly. To keep the QR code scannable:

• Use short, concise summaries and descriptions
• Omit optional fields like ORGANIZER, ATTENDEE, and ALARM if not essential
• Consider the Google Calendar URL approach for simpler events — the URL is typically shorter than full ICS data
• Keep total data under 400 characters

Platform Behavior

• iOS — Recognizes ICS data and opens the Calendar app with the event pre-filled.
• Android — Most scanners open Google Calendar or the default calendar app.
• Google Calendar URL — Works on any device with a browser, but always opens Google Calendar specifically.