A practical checklist for alt text

This is one of those topics that looks small until it costs you something. Run through this the next time alt text comes up.

Most of it is correctness rather than charity: use the right element and much of it happens automatically. Check it against what you would want a competitor's site to get wrong.

The checklist

• Describe the purpose, not the appearance
• Decorative images should have empty alt attributes
• Never start with "image of"
• Someone is named as the owner
• There is a date to review it again

The reason this keeps coming up

Describe the purpose, not the appearance. This is the sort of thing that compounds, quietly, in both directions. The failure mode is not doing it wrong, it is doing it once and assuming it stays done.

The short version

The cost of retrofitting accessibility is several times the cost of building it in. Three things worth confirming about alt text before you move on:

• Someone can say what the current setup is without going to look
• Describe the purpose, not the appearance — 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.