Alt text: the questions we get asked most

This is cheap to get right at the start and expensive to retrofit. The questions about alt text that come up most often on our calls.

The cost of retrofitting accessibility is several times the cost of building it in. Anything you cannot measure here, you are deciding by taste, which is fine as long as everyone knows it.

Do we need to care about this?

Describe the purpose, not the appearance. It is worth being explicit about, because assumptions differ quietly. Assume whoever inherits this will have half your context and none of your patience.

Can it wait until after launch?

Occasionally. More often the post-launch version costs several times the pre-launch one. Small and consistent beats large and occasional here.

How do we know it is working?

Never start with "image of". There is a version of this that is over-engineered, and it is worth avoiding. If it only works because one person remembers to do something, it does not work yet.

The short version

Most of it is correctness rather than charity: use the right element and much of it happens automatically. Three things worth confirming about alt text before you move on:

• Someone can say what the current setup is without going to look
• Never start with "image of" — and you know whether that is true here
• There is a way to tell whether the last change to this helped

Most of the value here comes from doing the first two things, not all of them.