Post #2095907

2026-05-06 08:18 UTC

I just saw an account posting a link and adding alt text to the post that described the link image. Then I had the idea: Images on websites have alt tags, therefore it should be possible to take the alt tag from the preview image and display it on mastodon automatically. Or not? #fediverse #mastodon #accessibility #a11y

Replies (1)

@mallonbacka@hachyderm.io 2026-05-06 09:47

@kleisli@mastodon.social the preview image is often configured independently with meta tags, and might not be on the target page at all. If the image was taken from the page, there’s no technical reason that this idea wouldn’t work. If the target image is set with meta tags, then it’s possible to set another meta tag, og:image:alt, according to the spec (https://ogp.me/) but a lot of platforms choose not to support this for various reasons. Finally, if the image is part of a link, the standards focus on the link (including the image) needing an accessible name which describes the purpose of the link, rather than the contents of the image (standards are about minimally not having barriers, rather than creating a perfectly identical experience). The assumption is that whenever the preview image covers is either in the title of the page (the share text) or also available on the page, if you follow the link. So, this isn’t a bad idea, but the current situation is considered an ok compromise, too.

Open ##2775533