Storyline 3 : How to convert PNG files to JPEG

Jan 19, 2018

When publishing My Storyline courses on HTML5 format, I am having an issue with pictures that are displayed after a couple of seconds.

Looking at the published folder nearly all pictures in my course are being created as png files. And those files, even in low resolution are quite large.

For the same file: file size is 957Ko as png and 107Ko as jpeg.

I would like to have all my pictures created as jpeg files while publishing. Is this existing? If not can this be included for future developpement?



29 Replies
Hubert de Vregille

Hi Alyssa,

I have populate my course by importing pictures I had on a powerpoint.

When publishing the course, those pictures are png files. Even if they are at low resolution their size is pretty high compared to the equivalent jpeg file.

I am having a large number of pictures, so I will not be able to treat them 1 by 1. This is becoming important as with the stoppage of flash, we will need to publish on html5. With large picture, we are having issues to use the courses: the pictures aree very slow to be displaid.

This fonctionnality is existing in other equivalent software, and would be needed with the extensive usage of HTML5.

Alyssa Gomez

Hi Hubert,

Thanks so much for clarifying that. 

The Image Quality slider that you see within the Publish Quality window only impacts JPEG/JPG files, not PNG files. 

The reason you're seeing increased image sizes is because the resolution at which we publish PNG files has changed for the HTML5 player in Storyline 3 and Storyline 360. 

I really appreciate your feedback and can certainly understand why this would be an important feature for you. I'll be sure to pass all of this along to my team as we consider new features in future updates!

Martin Iwinski

I am having the same issue. Our LMS has a 150 KB/s average bandwidth and publishing HTML5 content with nice graphic backgrounds causes issues. I import .jpeg images to my course and they all get converted into .png's.

The problem is that it can take several seconds to load a slide because of this. The .jpeg version could be 100KB, but the .png that is exported is around 800KB! Huge difference and quality is the same.

PNG's are good for icons and transparency images, but pictures, that's where .jpeg shines. I hope this is resolved soon because our users aren't getting a good experience with this slow loading.

Martin Iwinski

Hi Leslie,

I have attached a sample of the course. Each of the images are .png files when I export as HTML5 with Flash fallback. The size of the images are roughly 800kb, which causes them to load slowly on our LMS. Is there a way to limit image size or format when publishing HTML5? Or have the system be smart enough to know what should be .png and .jpg?

Leslie McKerchie

Thanks for sharing the details and your sample .story file Martin.

I've opened up a support case on your behalf so that one of our support engineers can take a look and best assist you.

Be on the lookout for an e-mail from :)

I did peek at your output file and it looks like the settings were a little different than I expected.

Looks like it's published for the Web > Flash with HTML5 fallback and AMP > and an increased image quality setting.

Have you taken a look at reducing the quality settings to see if that gets you back in ranges you expected? Again, I did open a case for you so that someone can take a look with you :)

Julien Loyer

Hi Alyssa,

I am using Storyline 2 and 3 but I think I will use Storyline 3 later because we can choose different format of publication. It's interesting for my work.

I'm interested to publish with HTML5 format because Adobe Flash will finish soon... And we need to play the videos/animations after this Flash stop.

Martin Iwinski

Yes, we have the same problem as Julien at our company. When we use Storyline 360 and publish content to HTML5 with Flash backup, Storyline publishes the content very innefficiently by converting ALL images into PNG's.

Problem with all PNG's is that the compression is non-existant and photos end up being almost 10x more kilobytes than of a JPEG image file (which is compressed). It would be nice to be able to have Storyline automatically know which files are photos and which ones are icons and less complex graphics, then choose the type of graphic export type.

Our course load times suffer because of these innefficient photo exports in Storyline 360. If there could be an update to get Storyline to export photos in JPEG format (with adjustable compression), that would be a HUGE help.

Crystal Horn

Hi there, Ted.  In Martin's case, when he published his file to his local drive, his files were not converted to PNGs.  Can you confirm...

If you can share your .story file here, I'm happy to test and see what's happening!

Crystal Horn

Thanks for those details, Ted!  The .jpg files remained intact in my own file when publishing to HTML5 only, both classic and modern player.  Can you use the Add Attachment button here to share your .story file with me? 

When you reply via email, attachments aren't included.  Your email signature with contact info is in the discussion, though, so feel free to edit it out!

Katie Riggio

Welcome, Primo. Happy to help investigate!

A few questions to help us narrow down why Storyline is converting .jpeg files to .png ones:

Additionally, would you mind sharing your .story file so I can try to replicate the behavior? You can share it publicly here, or send it to me privately by using this upload link. I'll delete it after troubleshooting.