Using ‘alt’ text to describe images is as important today as it ever was, and not just because of SEO. Alternative text is primarily about web accessibility; visually impaired users using screen readers need it to have an on-page image described. In addition, ‘alt’ text is displayed in place of an image if the file cannot be loaded. And yes, the text helps search engine crawlers.
What does ‘alt’ text look like? To a conventional web user, it lives behind the scenes and is invisible. If I look at the BBC News home page today, I see a photo of two politicians. Investigating the HTML page source, however, immediately after the image link it says:
alt="Boris Johnson and Jeremy Corbyn"
This is the ‘alt’ text for the image. To be honest, it’s not very descriptive, but in this case that may be unnecessary. At least it’s there.
You’ll be able to specify the ‘alt’ text for an image when you import it into your website’s content management system. General recommendations include keeping it to the point (100 characters is plenty) and using the page or story’s keywords. Don’t say ‘A picture of…’ as that’s taken for granted.
It’s a simple thing, but often forgotten.