Limit on Characters for Alt text

Why is there a limit on characters in Alt text? I am developing content for a chemistry course in which the images often times require fairly long text to fully describe. Often times I can not include all the text needed because of the limit on characters. Being an accessibility issue,  is it possible to change it so that the number of characters is not limited in alt text.

Supporter votes Members of the Supporter Network can vote for feature requests. When the supporter network has generated sufficient funding for the top voted feature request it will normally be implemented and released. More about the H5P Supporter Network
icc's picture

I don't think there's any particular reason for this, it was just the default max for all input field. I do agree that it's a little bit short in many scenarios. What do you think the new max should be, 1024 or 2048?

It would nice to have the max to be 2048. We are adding many graphs and diagrams that require long descriptions but the limit on characters not letting us do that. we are kind of stuck. Any suggestions?

This would be very helpful to us too. I work in a language lab, and sometimes professors ask me to adapt exercises where students have to do reading comprehension of images from newspaper ads and posters and such. The alt text isn't anywhere near enough for those—I'm having to design alternative exercises with the transcriptions. I would like to see this problem get more traction. Accessibility is extremely important and this is a pretty big hindrance to it.

icc's picture

I've done some research and it seems the recommended WCAG max length varies depending on the language, however, all of the recommendations are around 100 characters (100 for English, 115 for German, and 90 for Korean). I believe this has to do with how accessibility tools work, and as far as I'm aware you cannot "navigate within" these text strings with a screen reader like you can in other texts. This leads me to believe that it's probably better to use the alt text as a reference somewhere in a longer text if a longer explanation or context is required.

For those of you using large images that can be broken into smaller parts, in some capacity, I've discovered that cutting up the images and putting them into an Image Slider—each segment with its own alt text—works pretty well and looks pretty good. It worked for the reading comprehension posters and such, although I realize this wouldn't work at all for a graph or a chart.