Captions causing very slow initial load


We have a course developed in storyline that has audio on each slide, along with captions. When loading the file in the browser / via an LMS the initial load is very slow, after inspecting the network tab we noticed 100+ requests to *_captions.js files, and course won't begin until all the files have completed loading.

Has anyone run into this? and is there a solution to prevent storyline from pre-loading all of these files and instead load them when needed?


3 Replies
Ren Gomez

Hi Ian,

Thanks for reaching out and sharing that image of what you're seeing in the output! Do you have anything out of the ordinary, such as Javascript, in your slides?

Caption.js files don't usually get generated, so if you're able to share your file with our team, we can dig in and figure out what is happening here!

Share your file with us.
Ian Taylor

Hi Ren,

Thanks for the response and sorry for the delay.

The course doesn't have any out of the ordinary Javascript. I have included a simple .story file  with 2 slides which have captions enabled, publishing this file for the web will generate 2 *_captions.js files which are loaded during the initial load.

We ended up developing a script that combines all the caption files into a single file which means we only need to wait for 1 file to load vs 100+ for our large course. This brought the course from taking ~60 seconds to load down to ~10 seconds.