"We want everyone to have a safe experience on Twitter," the company said in a tweet. "APNGs were fun, but they don't respect autoplay settings, so we're removing the ability to add them to tweets. This is for the safety of people with sensitivity to motion and flashing imagery, including those with epilepsy." Twitter also said APNGs used up a lot of data, and could in some circumstances cause app crashes.
To be clear: you'll still be able to add animated images to your tweets, you'll just need to fall back on GIFs. Since most people already use GIFs as their go-to for sharing clips and reactions, the update is unlikely to change how the majority use the platform.
To make up for the loss of the added functionality that comes with APNGs, Twitter says it's working on adding alt-text to GIFs, which will help make them more accessible to people who depend on screen readers to navigate the internet. It's also looking into building a similar feature that's "better for you and your Twitter experience."
The move probably won't make Twitter completely safe for photo-sensitive individuals since trolls have used GIFs in the past to try and harm people. However, the fact that APNGs were able to bypass the site's autoplay protections made them particularly susceptible to abuse.
Update, 5:15PM ET: This post and its headline have been updated to note Twitter says that it isn't aware of anyone misusing the APNG format to try and trigger seizures; it just wants to make sure no one does so going forward.