This was a common problem in the early days of the internet, when download speeds were mind-numbingly slow and people were apt to turn off image downloads in their browsers to speed things up. Today, some people still choose to disable image display in their smartphone browsers in order to preserve their data plans.
But there’s a much more common modern scenario that makes alt text absolutely crucial: visitors to your site who can’t see. This includes both people with visual disabilities, who navigate the web using screen reader technology, and the web-crawling search engine robots who are in charge of scoring your website and controlling your search rank.
If you’ve placed an image on a page, presumably it’s because that image adds to the page in some way, whether it’s a helpful diagram central to the page’s thesis, an eye-catching way to make navigational options obvious, or just setting a mood. How are SEO bots and the vision-impaired to know whether they are missing key information about your page if you don’t tell them what’s in the images you chose to put on it? With alt text, every visitor to your site can get the full picture.
On the human side, describing images through alt text is a simple but powerful way to improve the lives of those with disabilities. On the business side, it can raise your company reputation both with humans and the robots who decide where in the search rankings your company pages will be displayed.
Now that we know what alt text is and why it’s needed, let’s look at some examples.
What Does Good Alt Text Look Like?
The best alt text is text that accurately describes the image. Keep it as brief as possible, but include all relevant details. Typically, alt text is 3-10 words long, but if you need it you can even fit several sentences. Punctuation is allowed. If there are words embedded in the image, you must include those words in the alt text.