Prezi Classic API missing in WebGL


Hello Prezi Team. I noticed that the Prezi Classic API is missing from the WebGL version. This is really disappointing as this breaks training tools that utilize Prezi’s API. The worst part is that the Flash version will not run any more in Chrome resulting in all Prezi Presentations launching in WebGL mode. Are you looking to implement this feature? Currently, many Prezi business users utilize the API feature via and the missing feature removes Prezi as an option for them to use natively in their LMS.

Additionally, are there any plans to add the Prezi API to Prezi Next?


Last week we had some technical difficulties with our API that should be fixed now. We’ve tested a presentation on and it seemed to work on our end. Please let us know if you experience it differently so that we can notify the responsible team.

As for adding the API to Prezi Next, I’ve also passed this request to the dedicated engineering team.


Hello Vanda,

It looks like the isMovingChange event does not fire in the WebGL version. I see it is not called out as a function to watch, however, it is listed in the downloadable API JS file.

Is this something that will be updated? If not, please let me know.



Thanks for reporting this, our engineering team had a look into this, it should be working now.

Could you please share a link with us where you use this API?


Hello Vanda,

Thank you for forwarding on the issue to the Prezi Engineers and resolving the API issues so quickly.

Another difference with the API is the order the events are called. This is specifically a problem because now the contentready event is called after the first page is set to 0. Also, previously the contentready event was called twice. Once upon initial load, and once when all of the content was fully loaded. This is a problem because I observe the currentStepChange event, and since it fires before the content loaded event, step 0 is actually loaded first instead of being able to set the slide and then having it go to that immediately like in the old Flash version.

Additionally, Prezi API does not run in IE9 or IE10 anymore. There is a warning about unsupported debug method in one of the CDN api/files under directory.

If you want to test the API the same way I do, you can go to, enter a Prezi ID or URL and click download. Then create a free account at and upload the course package. There is an “Add Content” button in the upper right corner. Click on that and then select “Import SCORM…” Next upload the package. Next select “Library” from the left hand menu and click on the uploaded course. Then click “Launch” and the course will launch in a popup window and allow the popup windows from the domain if asked. Finally, navigate through the Prezi until you get to the last page and a popup window will be displayed and you can click close.


Thanks for the details @Dan_White1 , we’ve passed everything on to our engineers and will get back to you soon.


@Dan_White1 please note that Prezi API is no longer supported in Internet Explorer but Edge should work fine.