Writing good alt text on the Fediverse

Alt text (short for alternate text) is text that describes an image or video so that people with vision problems can still enjoy the post. This page discusses why it is necessary, how to do it properly, and how to let people know if they aren't.

Why is it needed/what's it for?

Imagine you have issues seeing, so you use a screen reader to read out the text of posts to you. Someone posts a funny meme, and all your friends are talking about it in the replies section. If the post has no alt text (or poor alt text), you will have no idea what is going on or what's so funny. On the other hand: if the post has good alt text, you will be able to hear a description of the meme read to you and so you can appreciate it the same as sighted folks! Alt text is just the right thing to do, it makes sure everyone can enjoy your posts equally!

Good vs bad alt text

Below is an image and a table. The table shows various possible alt texts for the image, and ranks them on a scale, describing them and how they could be improved if possible.

Please click here if your browser cannot display inline images.
The image and "exceptional" alt text are from this post. Give them a follow!

Ranking	Text	Explanation
Missing	(No alt text is present or the alt text is blank)	NEVER, EVER do this. Absolutely never. There is not a justifiable reason for adding no alt text.
Irrelevant	picture	Also do not do this. Do not put "funny meme" as alt text for a meme or "nature scene" as a caption for a nature photo. This doesn't help anyone.
Poor	person holding pot	It's a good start, but it needs some work. Where is the person? What sort of pot is it? What color is the pot? Does the picture have other distinctive elements?
Okay	A person standing outside holding a pot	You're getting there! Be a bit more descriptive and go into detail more.
Good	A person stands outside in the sun, holding a terracotta pot. Plants are visible in the background.	Almost there! Just a bit more describing!
Exceptional!	A photo of me standing in our yard on a bright, sunny day, holding a large, spherical hand-crafted terracotta pottery jar with a decorative knob, wearing gloves and a gray t-shirt. Only my chin down to my knees are visible behind the large pot. Green tree leaves and a bit of blue sky are blurred in the background.	You did it! This alt text describes the image well, and allows everyone to appreciate the post in all its splendor!

Your alt text should always be "good" level, but try to aim for "exceptional".

And now, common excuses

I don't have enough time to write alt text!

Yes you do. (Unless you're on the run from a dinosaur. Why are you posting on the Fediverse if you're running from a dinosaur? You know velociraptors can open doors, right?) Writing "exceptional"-level alt text takes about 2 minutes, at most. Actually, you can probably wedge a chair under the door to buy you that much time if you're in that velociraptor situation I described earlier. Velociraptor or not, you can almost certainly find enough time to whip up some alt text no matter how busy you may be (or how many dinosaurs you have chasing you, or whatever).

Alt text ruins the joke!

In what way? You don't have to explain why a meme is funny, you just have to describe the meme in a way it can be understood via the alt text. You do need to describe the meme so that people can read (or listen to) that description and still be able to get the joke. You don't need to explain why it's funny.

The software I'm using doesn't have an alt text feature!

If your software has a text or description field along with the image, you can use that. Also talk to the owner of that software and tell them to get their sh

t together.

P.S.: Please do not AI-generate billboards with text on them and then put no alt text on the image instead of just making a text post. There are so many things wrong with that (you know who you are).
P.P.S.: If you see someone with bad alt text, please direct them to this page. And if you have been directed to this page, it was not in malice, just a friendly reminder. Here's a template you can use:

Hey! Please add (better) alt text to your image. For more info, check out this page: http://bluepixelcomputing.com:8141/fedi/alt_text.htm

My web counter is on strike. Sorry :P This page was last updated April 24th, 2025 (c) GroupNebula563. Please do not reproduce this page without crediting me. Feedback welcome! Please let me know of ideas/improvements at @GroupNebula563@mastodon.social