Bluesky, gifs, and autogenerated alt text
Hey there! Not sure what alt text is or why it's important? Start with my article here: Alt text 101 for Bluesky.
If you post gifs on Bluesky, don't settle for the autogenerated alt text that's provided; it's usually crap! The purpose of alt text is to give context to those who can't see images — i.e. people using screen reader software or other assistive tech. The autogenerated text Bluesky provides usually misses the point of the gif, i.e. what's important about it for the context of your post.
I use this hat tip gif (above) in replies all the time, and the alt text that's provided by Bluesky is garbage: "a man wearing a top hat and a vest is standing in front of a pile of rocks." It doesn't say that the guy is tipping his hat! That's the only important thing about this gif, if you think about why I'm posting it at people. Get it?
Describing what the pic is visually — the clothes, the rocks* — is mostly useless to a person who can't see it. The action, the meaning, are what's needed to give the person context. So when you post a gif, ask yourself what you're communicating with it, and put that in the alt text.
*Someone pointed out: that's not even rocks, probably! All of this Bluesky alt text is probably AI-generated, meaning it has no idea what the point of any of these images are.
When I post the hat tip gif, I just type in "Benedict Cumberbatch hat tip" for the alt text. I could add a lot more detail, but it's not really important. If a person using screen reader software hears the post I'm replying to, and then they hear that I've replied with a gif of someone tipping their hat, that tells the whole story.
The general rule of thumb for alt text (like on websites) is that about 150 characters worth of details will usually provide the user with the right amount of context. 150 is a lot! I could totally write something like "English actor Benedict Cumberbatch, wearing 19th-century-style clothing including a dark coat and top hat, smiling and tipping his hat. He's on a ship; there are objects secured with netting on the wall of the ship behind him, and the ocean is visible beyond that." (That's over 250 characters; definitely overkill.)
Is any of that extra detail going to be useful to anyone? Does it help make it even more clear why I'm posting this gif? Certainly not. Does it hurt to add all that extra stuff? No. But it's really not important, and not a good use of anyone's time.
One important point I make regarding alt text and social media is that if we urge people to write very detailed alt text, there's a good chance some people will be lazy and just skip it all together. So I think it's okay to encourage people to write alt text that's very brief and to the point, just including enough info to make it make sense to a screen reader user.
One last thing! Consider this: the same pic might merit different alt text for different uses! If I posted the same Cumberbatch hat tip gif to someone who wrote, "Who wants to time-travel to the 19th century with me?" then it would be important that the alt text mention the style of clothing, for context! Get it? Alt text is communication!
– Manning
Questions/comments? Feel free to contact me at manning@manningkrull.com. I update these articles pretty frequently — best practices evolve over time as the world of digital quickly changes, and I always welcome insights from others.