AddEvent is an
Add to Calendar button,
a Subscribe to Calendar button
and Event Management

If you are looking for an “Add to Calendar” button or
a “Subscribe to Calendar” button or an API for on the fly event
creation or an Event Manager for your website or newsletters,
then look no further. AddEvent offers an easy, convenient
way to create event buttons. It's easy to use and install.

AddEvent was created in Palo Alto, California, May 2012 by
Michael Nilsson and is today considered to be the standard
“Add to Calendar” button on the Internet.

Try our buttons

Add to Calendar 12/10/2015 09:00 AM 12/10/2015 11:00 AM America/New_York Summary of the event

AddEvent example text.

This is the text entered in the event description field. The text can be plain text or simple formatted html. The AddEvent rendering engine converts and formats text beautifully and adjusts the formatting to the selected calendar media.

Example of a link

  • Many of our users use html to add lists like this one
  • HTML lists are converted into bullet lists
Location of the event Organizer Organizer e-mail false MM/DD/YYYY
Subscribe to Calendar

And our:

  • "Add to Calendar" + "Subscribe to Calendar" buttons for newsletters
  • Event Manager
  • Custom Templates
  • API for on the fly event creation

AddEvent is:

  • Easy to use and install
  • 100% themable
  • Timezone and DST compatible
  • The leading calendar widget in the world
  • Great support (we will actually help you)


You're in good company. Awesome Internet Superstars
and Offline Ninjas use AddEvent too


Install your new buttons in a few minutes

AddEvent helps you create an “Add to Calendar” or a “Subscribe to Calendar” button in a matter of minutes. Get started using our simple yet beautiful pre-built button or customize the design to fit your website or application. Do not worry about daylight savings time and time differences in all the different regions of the world - we have got it covered. AddEvent has been tested by millions of users and is entrusted by companies from San Francisco to Sydney.

Works everywhere

AddEvent is carefully crafted and optimized for the most common browsers, tablets and mobile devices. In our mindset we go "way back" and so does our optimization - our buttons are even optimized for Internet Explorer 6 (yes, some people in the world still use Internet Explorer 6).

What about newsletters, campaign management tools and social media like Facebook and Twitter?

Sharing your event on social medias like Facebook or Twitter is easy with our event management tool. Simply create your event and share it or insert the event link in your newsletters or campaign tools. With our event management tool you are able to provide links for direct downloads or create a landing page where your users can add your event to their calendar of choice.

Custom templates and Direct URL Method (API)

If you’re comfortable hand-coding HTML, then you can customize the apperance of the landing page. We have created simple block elements and tags which makes it fast and easy to setup your own design. You can create an unlimited number of templates.

Our Direct URL Method (API) is a method suitable for developers who develop their own newsletters, work with Flash, mobile development etc.


Non-commercial Usage - Free

If you want to use the "Add to Calendar" button for a personal website, your schools website, your personal blog or a non-profit organization then you do not need to become a Premium Member, just go on and use it.

Commercial Usage only $4.80 /month (if billed annually)

The AddEvent buttons, Event Manager and API is going to save you weeks of programming, so consider becoming a Premium Member. As a Premium Member our services become unbranded, you get access to all features and you support AddEvent to become even better.

Key Features Non-commercial Usage
Commercial Usage
Pre-built “Add to Calendar” button
Calendar generates & downloads Unlimited Unlimited
Timezone and DST compatible
SSL support (https)
Advanced javascript settings
Change labels in dropdown
Custom options in dropdown
Custom themes gallery
Custom CSS (ability to customize the button)
Event reminders in Outlook, iCalendar (MAC) etc.  
Recurring events in Outlook, iCalendar (MAC) etc.  

Pre-built “Subscribe to Calendar” button


Calendar generates & syncs   Unlimited
Timezone and DST compatible  
SSL support (https)  
Advanced javascript settings  
Change labels in dropdown  
Custom options in dropdown  
Custom themes gallery  
Custom CSS (ability to customize the button)  

Event Management Tool for newsletters and campaign tools, eg. MailChimp, Marketo, Salesforce, CampaignMonitor, flash, iPhone, Android etc.


Direct URL Method (API) for dynamic calendar creation with optional landing page  
Custom landing page for events  
All AddEvent branding removed  
Support   Priority


Building AddEvent with our users is the real deal to us.
We keep track with all changes made so our users are kept in the loop.

Update (Tuesday, November 10, 2015)


In the description field of the “Add to Calendar” button our users are able to add text which is transferred to the calendar service their users selected. Officially we used to only support plain text with HTML break tags, but we got a lot of requests from our users who wanted a nicer and better formatted output.

We have rewritten our content handler function and the handler now supports and converts HTML content as well as “bad formatted” text. Our new content handler basically looks at the content and determines if the content is good or badly formatted. On that basis it converts the content and tries to make it look great.

The content handler supports HTML tags. HTML tags are transferred directly as-is to iCalendar supported calendar clients (like Microsoft Outlook, Apple Calendar) and is converted to nice looking text in calendar clients that only supports text (like Google Calendar, Microsoft, Yahoo Calendar).

Update (Monday, October 26, 2015)


During the week we have observed (in our error reports) that our date validation is too strict. We just released a more loose date validation routine.

Update (Friday, October 23, 2015)


A user asked us to take a look at their all day events which didn't work correctly. On that basis we reviewed and corrected the "all day event" handler in our code base.

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