One Stack Exchange website on which I'm active has an ongoing project to fix the alt text all over the site to increase accessibility for vision-impaired users.

I'd just like to ask all of you to fix this before it becomes an issue, and include the alt text in any posts with pictures so that our content is more accessible to everyone. (This also means that we won't need to go back and fix this at a later point.)

You can run this query to find images on the main site that need fixing (although the database for the data explorer only updates weekly, so some more recent posts won't be there).

This is especially relevant for posts tagged , because most of the cited material in those posts will be in pictorial form.

Thank you.


2 Answers 2


I guess I'll throw my hat in.

Here's how I'll be doing it in my answers (here's an example):

  • Description. The [enter image description here] part serves two purposes.

    • Most important, it adds an attribute to the picture so that when the picture cannot be loaded, or when using a vision-impaired user software, the description will provide some information about what's going on on it (hat tip to @BESW for pointing this out). Because of this, you the prospective editors are encouraged to add meaningful descriptions for any pictures that are essential for your post. Nonessential, or purely decorative pictures should have their description field empty.

    • A "meaningful description" conveys the same information that the image is intended to convey. Think how you would describe the image to someone you're talking to over the phone: what would you tell them so what they hear over the phone makes sense in the context of the surrounding text.
      Note: the text that ends up in the alt attribute (in the generated HTML code) is not intended for long descriptions. If you need more than (roughly) 150 characters, add a description below the image, identify the image in the alternative text and add "see the description below (or something similar). E.g. ![sales graph for 'How to Get to the Top on Stack Exchange' for the years 2010-2020; see detailed description below][1].

    • The description eases the indexing of your images, so that when you have to edit replace one, it will be easier to locate it among the links at the bottom of your answer. Note that you can customise not only the description, but also the link, e.g. if you have [![description][foo]][bar] you can do two things:

    • Name your image in your references, so that your link looks like
      [foo]: https://i.sstatic.net/blabla.jpg "some comment"

    • You can add one thing as image, but clicking on it will lead you to different place1 (i. e. not Imgur). In this case, your in-text link looks like this:


      and your end-text links look like

      [foo]: https://imgur stuff/picture.jpg "some comment"


      [bar]: https://pottermore.com/stuff

  • The hover text. This part is what ordinary readers will be interested in. Note that this doesn't benefit the visually-impaired users (hat tip to @doppelgreener), so if the picture is self-explanatory, it is better to leave this field empty. In fact, the hovertext is a function that is better used sparingly - if you want to clarify something about the image, the place to do this is the question body.

The hovertext is edited in the end-text links by putting a comment in quotes directly after the link, like this:

 `[foo]: https://i.stackimgur.com/pic.jpg "your comment"`

Which will look like this (hover your cursor over it!):

[![Saitama in his natural state][Saitama]][5]
  • Transcript. In my understanding, this is the most important part, given the specific need @Stokhet has pointed out.

    After posting a pretty picture with fancy hover text, it comes down to explaining what exactly is going on the picture. Putting this in the hovertext is absurd, as sometimes a transcript may be a couple of paragraphs (damn you, Alan Moore!).

    The one thing I am not sure about is the content of the transcript. Two alternatives I see are:

    • Full transcript. This would require one to transcribe everything on particular slide, meaning all the speech bubbles, description bubbles, and even the graphical content. This is a lot of work, but I think this option is what we should be aiming for.

    • Short, synopsis-like description. In this case, you outline, in general terms, what is going on on the picture. This requires a bit less work (but more creativity), and could be less informative than the previous option. Note that this option is pointless if there are important quotes on the picture.

    In any case, it would be nice to put a transcript in a quote, directly after the picture. As Tsundoku and Laurel point out in the comment below, per the HTML standard the <sup> and <sub> tags shouldn't be used for this purpose.

1: Needless to say, abuse of this feature, including intentional misdirection of unsuspecting users to TVTropes, is punishable by death.

This answer uses the information from this answer over at Mi Yodeya, and the editing help page, especially the parts on images and links.

  • 2
    Small text (sub/sup) can be hard to read though, which is why I try to avoid it. I also think it's read like normal text to screen readers, so it can be confusing.
    – Laurel
    Commented Nov 20, 2021 at 17:46
  • @Laurel I've edited the answer to reflect your feedback. thanks! Commented Nov 20, 2021 at 21:20

Sure. There's a reason it tells you to provide an image description; it's better for people who can't see images for some reason, such as a browser not supporting it or any other reason. It takes 3 seconds to add when you upload it - just take the time and help make this site better!

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