Users can now add alternative text (alt-text) to images uploaded via iOS and Android Twitter apps. Alt-text allows people who are using assistive technologies like screen readers and alternate keyboards to understand what’s being displayed in a photo when they can’t see it.

When activated, this feature will let you add descriptions to all your images. You’ll see an “add description” option directly on your photo in the tweet composer.

You can turn on this feature in your app`s accessibility settings

Because a lack of alt-text excluded visually impaired users, some people tried to enact workarounds so all their followers could have a similar experience. Replying to tweets with photo descriptions was one way to add a description, or creating alternative Twitter handles that would describe what the main account tweeted.

Twitter’s move to add alt-text is helpful, but it’s still only available via mobile appsâ€"you can’t upload a photo to the Web and add a description yet, though Twitter has plans to bring it to Twitter.com in the future. The image descriptions are accessible across Twitter’s platforms, and in tweets syndicated on the Web.

Facebook also has the option to turn on descriptions for your images, and it’s working on AI tools that use image recognition to automatically identify what’s in an image.