When I built the Sound of Wonder website for DJ Scooby, accessibility was not a box to tick at the end. It was the brief. Scooby has dyslexia, so the whole site had to work for someone who finds a lot of the web hard going. That meant thinking about type, contrast, layout, and a small field most people ignore completely: alt text.
If you run your own WordPress site, you have seen it. You upload an image, and there is a box called alternative text. Most people leave it blank, or WordPress fills it with the filename. IMG_441.png. Job done, apparently.
It is not done. And filling it in properly takes about ten seconds once you know what it is for.
What alt text is actually for
Alt text is a written description of an image. Screen readers, the software that reads pages aloud for blind and partially sighted people, speak it out loud when they reach the image. No alt text means the person hears the filename, or nothing at all. They know something is there. They have no idea what.
It also shows up when an image fails to load on a slow connection. And Google reads it too, which I will come back to.
I test some of the pages I build with a screen reader myself. It is the quickest way to find out whether a design decision holds up. Listen to a page read aloud once and you will never leave a filename in the alt text field again.
The bad, the good, and the pointless
Here is a real one from the Sound of Wonder site. The image is a Polaroid camera with a processed photo of the Sound of Wonder logo sitting in it.
The bad version is what WordPress gives you by default: IMG_441.png. A screen reader will say that out loud, letter by letter and number by number. It tells the listener nothing.
The good version is what I wrote: “Picture of instant camera with a photo of the Sound Of Wonder skull”. Someone hearing that knows exactly what is on the page. They get the same information a sighted visitor gets.
Then there is the pointless version, which trips people up more than the bad one. Something like “image of a photo picture”. Or stuffing the box with keywords because someone once told you it helps with Google. Both are worse than useless. The listener already knows it is an image. The screen reader tells them that. Describe what is in it, not what it is.
A decent test: imagine reading the page down the phone to a friend. When you get to the image, what would you say? That is your alt text.
When to leave it empty
Not every image needs a description. Some images are decoration, not content.
On my typography site, webtypographysolutions.com, there are lots of small decorative lines between sections. They are visual punctuation. They break the page up for people who can see them, and they carry no meaning at all.
If I gave each one alt text, a screen reader would announce “decorative line” a dozen times down the page. That is noise, not access. So those images have an empty alt text field, on purpose, and the screen reader skips straight past them.
The rule is simple. If the image carries information, describe it. If it is decoration, leave the field empty. Empty is a decision, not a shortcut.
One thing to know: in WordPress, an empty field is fine for this. Do not write “decorative” or “spacer” in the box. Leave it blank and move on.
The SEO bit
Google cannot see your images. It reads the alt text to work out what they are, and that plays a part in whether your images show up in search results.
I will be straight with you: I have not got numbers from my own sites showing alt text bringing in traffic. It is a side effect, not a strategy. But it costs you nothing. You are writing the description anyway, for the people who need it. Google understanding your page a bit better is a bonus.
Which is the right way round. Write for people first. The robots can have the leftovers.
Ten seconds per image
That is the whole thing. When you upload an image, describe what is in it as if you were reading the page to someone down the phone. Leave decoration blank. Do not stuff keywords.
It takes about ten seconds per image, and it means your site works for people you might never hear from. On the Sound of Wonder build, that was the point from day one. On your site, it can just be a habit.
