In an ideal world, all image descriptions would happen in the “alt text.” Which is like, when you’re adding an image to your website, you go to the <img> tag and add alt=”image description goes here” Alt text is super great for screen readers because they know that it’s an image, and they read the alt text accordingly. It’s also nice to configure things this way because then there is less text-clutter, which can otherwise be a pain to folks with certain learning disabilites/ADHD.
However, this is very often not an option for tumblr-users. When you’re uploading a photo post, for example, you don’t even get the opportunity to add alt text. But there are things you can do to compensate:
- Put the image descriptions right below the picture. Even if it’s a reblog, you should just add in the description before the blockquotes that have everybody else’s commentary. Because of how tumblr is set up, the description will be credited to you. This helps sighted folks who skip around when they’re reading to know what not to read, and it also allows people using screenreaders to know what the image looks like before they hear everything other people have to say about it.
- Let people know that it’s an image description by following the convention “[image:…].”
- Put a paragraph break between the image description and the commentary. (It shouldn’t function as the first sentence of some longer comment).
- If you can, add the alt text to images you upload. When you upload an image on a non-image post, tumblr gives you a space to add in an image description. That’s where it should go! If you’re worried that a sighted follower might not realize that you have an image description already (and therefore they might re-write one), you can put [image described in alt text] below.
When the alt text is blank, screen readers just read out the url—so it saves your blind readers some time if they get to hear the image description instead. However, this isn’t always possible on tumblr, unless you’re uploading an image on a text/link post. So when the alt text fails, following these conventions maximize the accessibility for blind readers AND readers with disabilities that hinder their processing large amounts of text.