Alternative text test

What is it?

This test checks for the correct use of alternative text, which is text that describes your media to search engines and people with disabilities.

Why it matters

Alternative text is crucial for two reasons:

  • SEO – Search engines are unable to understand images, video and audio like a person can. Alternative text tells them what your media means, which gives them extra opportunity to rank you for that content.
  • Accessibility – Many users are unable to experience media due to a disability, such as a visual or hearing impairment. These users depend upon alternative text to describe media used by a website. Modern accessibility standards, such as WCAG, require the appropriate use of appropriate alternative text.

How to use it

Insites lists all the media (images, video, audio) with alternative text issues in a table. Typically this includes images that are missing alternative text altogether, as well as some which have low-quality alternative text that might need improving.

For each word, you can click on:

  • Magnifying glass – this opens the Inspector, which shows you where the media appears on a page.
  • Ignore – this will ignore the alternative text (or lack of it) for this media. For example, you may not need alternative text for a certain media.
  • Number of pages – this will show you a list of all the pages with this word.

If you open the Inspector, you will see the media with issues highlighted on a specific page:

Here you can click Ignore to ignore the media if you decide.

Empty alternative text

By default, this test will consider explicitly defined empty alternative text as valid, e.g.

<img src="example.png" alt="">

This allows you to explicitly define that an image could have alternative text, but that you chose not to specify any as it wasn’t appropriate.

If you prefer you can tell Insites to reject empty alternative text. Click on Settings > Alternative text settings and check the Don’t allow empty alternative text box.

Weak alternative text

When Insites says that alternative text is weak, it has found one of the following:

  • Filenames – e.g. “image.png”
  • Code – e.g. “foo__bar-1”
  • URLs – e.g. “”
  • Generic – e.g. “image” or “picture”

Most of the time, so-called “weak” alternative text is not effective for end users, but there can be exceptions. You can click Ignore to ignore a specific piece of weak alternative text if you wish.

Best practice

The amount and quality of alternative text you include will depend on your website. Generally we recommend including alternative text for every piece of media, except for images that are purely decorative. As a general rule – if you removed the media entirely, would it matter? If not, you can probably ignore that media, or specify empty alternative text.

Sites which are especially concerned with SEO or accessibility should consider alternative text an early priority.