How are alt-text and image descriptions in the Fediverse different from other places?

Those of you who may have learned about alt-text and how it should be done outside the Fediverse may be confused or outright shocked about how alt-text is done on Mastodon and some "Mastodon satellites" like Pixelfed. It isn't necessarily short, concise and to the point. Instead, it often goes into great detail. What should be described in 100-200 characters by Web standards is often described in 600-1,000 characters, sometimes even more, often with some added whimsy.

And these overly long alt-texts are applauded. They are praised. They are cheered for. They are loved much more than they are criticised. Even the Alt-Text Hall of Fame presents alt-texts which, by Web standards, are catastrophically long.

In the rare occasions that professional Web designers with accessibility certificates or accessibility experts find this out, they are usually shocked. Mastodon is "doing it all wrong".

But why is that so? And why does it stay to be so?

Standards set by laypeople rather than experts

Most importantly, that's because Mastodon didn't get its alt-text culture from professional Web designers with accessibility certificates or from other accessibility experts. It got it from amateurs, from complete laypeople, from regular users who wanted to make the Fediverse as accessible and inclusive as corporate social media are made hostile towards the disabled by its own users.

Experts had no saying in this whatsoever.

In fact, in establishing Mastodon's alt-text culture, these laypeople didn't even look up existing accessibility standards and enforce them. Their motto was, "Just do it. Anything is better than nothing."

"We've got 1,500 characters, so let's use them"

In order to outshine places like Twitter, Facebook and Instagram in terms of inclusion, many also decided to go well beyond the oft-cited 80 or 125 or even 200 characters as the upper limit for alt-texts. For one, blind users said that today's screen readers do not have any built-in arbitrary character limit for alt-texts anymore. Besides, Mastodon offers 1,500 characters of alt-text per image, so why limit yourself to only 200?

Alt-text guidelines for the Web were half-invalid on Mastodon anyway. They say that image explanations go into a caption below the image, and that longer image descriptions must go into the text itself or onto a separate page which then must be linked to.

However, Mastodon has no support for captions. In fact, nothing in the Fediverse can create captions, and nothing in the Fediverse can render them. Not even (streams) and Forte, descendants of Hubzilla which allow for HTML in posts, have any support for captions.

On top of this, Mastodon has no room for long image descriptions or explanations in posts. By design, it only allows for 500 characters per post, minus hashtags, minus mentions, even minus the content warning. It's old-school microblogging after all. It doesn't have any way of creating, storing and linking extra documents either, and not even nearly everyone has some Web space to park external image description documents on.

In fact, linking to external descriptions or external explanations is frowned upon on Mastodon. Anything external might not be sufficiently accessible. Besides, for those who use Mastodon in a dedicated app rather than through the Web interface, and they're the huge majority, anything external is a nuisance because it makes a Web browser pop up. No, any and all information about an image must be in the same place as the image itself.

Thus, on vanilla Mastodon, the alt-text is the only available place for a long image description. This is also why it's completely normal on Mastodon to explain things in the alt-text although this is completely wrong because not everyone can access alt-text.

Just about everything else in the Fediverse that does some kind of "blogging" has a much higher character limit and room for long image descriptions and explanations. But this leads to "long posts", as in posts with more than 500 characters, which irritate not few Mastodon users to such degrees that they justify their own sanctions.

Why experts don't step in

Speaking of sanctions, why don't accessibility experts step in and do something against this? Where were they when alt-text was introduced into Mastodon's culture?

When alt-text was introduced into Mastodon's culture, they didn't even know that Mastodon exists. When they discovered Mastodon, it was too late: The Mastodon community already did alt-texts its own way, completely disregarding any existing standards, just like Mastodon itself disregards standards left and right and forces its own "standards" upon the Fediverse.

Also, accessibility experts can try to tell Mastodon users how to do it right all they want. But they have to tell them one by one because none of them has as much reach as George Takei or Eugen Rochko himself. Also, Mastodon users will reply that the way images must be described according to Web standards doesn't work on Mastodon with only 500 characters per post. And nobody on Mastodon is willing to move elsewhere in the Fediverse with a higher character limit just so that they can describe and explain images properly.

Lastly, accessibility experts are not an authority of any kind anyway. All they do is give advice or criticise the existing practices every now and then. But they don't enforce the Web standard way.

The power of Mastodon's alt-text police

At the same time, Mastodon's "alt-text police" enforces alt-texts by means of various kinds of sanctions. And they certainly don't enforce the Web standard way. I have seen a whole lot of posts with alt-texts, I have seen a whole lot of reactions upon posts with alt-texts, but I have never seen someone refusing to boost a post or even unfollowing, muting, blocking or attacking someone for an alt-text that greatly exceeds 200 characters without including a long text transcript.

The alt-text police started by sanctioning missing alt-text. Their next step was to sanction useless, non-sense alt-text, including when the alt-text is identical to the post text because some smartphone app simply automatically copies the post text into each alt-text. They continued by also sanctioning vague and/or inaccurate alt-text written by an AI and not checked and corrected by a human afterwards. And it appears like they have started to go against human-written alt-text that isn't sufficiently accurate and/or detailed.

They will likely continue to raise their standards, and their standards are based on Mastodon's standards and not on WCAG standards. If they do, then WCAG 2.2-compliant alt-text will be sanctioned for not being detailed enough.

Opposing them is dangerous. On top of sanctioning your insufficient alt-text, they will also call you out as ableist and add even more sanctions because you've dared oppose those who enforce accessibility and inclusivity in the Fediverse.

The safe way

If you regularly have to describe images at greater detail and/or explain it, and you want to play it safe, here's some advice:

• If you're on vanilla Mastodon with a character limit of 500, move somewhere in the Fediverse with a significantly higher character limit. Hint: All instances of Misskey and Sharkey have no fewer than 3,000 characters, and all instances of Pleroma and Akkoma have at least 5,000 characters. Don't worry, if it's in the Fediverse, it's also connected to Mastodon, and you can follow and be followed by the same people as on Mastodon.
• Describe your images twice, once in the alt-text and once in the post text. Explanations and other additional information go into the post text.
• Always mention in the alt-text that there is also a longer, more detailed image description in the post text. If it contains explanations, also mention these. Some members of the alt-text police may still use interfaces that don't hide images behind content warnings, so if you put your post behind a content warning, they will see the image, they will see the alt-ext, but they won't see the post with the long description immediately.
• If your post exceeds 500 characters, and it will, put it behind a long post content warning, and add the hashtag #LongPost.
• For now, you can keep the visual description in the alt-text short. But beware of the alt-text police raising their standards further.
• Don't worry about professional accessibility experts. They can't harm you. But do try to stay ahead of the alt-text police and their minimum standards because they've got the power to cut deeply into your reach and even ruin your reputation all across the Fediverse.