We hope your job is mostly a pleasure. But unless you’re extraordinarily lucky in your choice of work, chances are you sometimes have to do really boring stuff just because it has to be done. For me, adding ALT text to images on websites is in that category. There are few things I find less exciting than writing short descriptions of images: “Cow standing next to tree in field.” “Team leader smiles as she delivers presentation to work colleagues.” “Man in white coat demonstrates toothpaste brand.”
So it’s not my favourite part of the content creation process yet I’m prepared to do it, all the same. Why? Because it helps users, and because it helps the search engine optimisation of your site, and therefore its search rankings.
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Why you need to add ALT text to images
As noted above, ALT text (also known as ALT tags) is descriptive text about images – text that briefly described what is in the image. And images are a vital part of a successful and effective web design.
But who needs that? Can’t people just look at the images and figure out for themselves what they show?
First of all, not everyone can in fact look at the images and see what they show. A substantial number of your users are likely to be visually impaired, and the proportion of such users is likely to grow in an aging population. Many visually impaired users rely on screen readers, which read out the text to the screen on them. If there are images on the screen without ALT text, then the screen reader will ignore the images completely. If the images include ALT text, then the screen reader will read out that text, at least giving visually impaired users a clue about what the image contains.
Second, Google’s search bots are also unaware of what is portrayed on images. Therefore, Google will not take images into account when determining search rankings unless ALT text is included along with those images.
If ALT text is included, the Google bots will pick this up and rank the images for inclusion in Google image search on the basis of the ALT text. As with ‘standard’ Google searches, users are much more likely to click on the first few images that come up in the image search results – and hence be taken through to the websites that contain those images.
So that’s why you need ALT text descriptions of images. But how should that ALT text be written?
Writing High-Quality ALT text
Fundamentally, your ALT text needs to be detailed, specific, and clear – that’s what helps users, and helps Google’s search bots as well. If your web page includes an image of a suit, and you just use “suit” as the ALT text, that isn’t specific enough to be useful. If you say, for example, “Men’s business suit including jacket and trousers”, that phrase contains the sort of specific keywords that will help the image come up in a search for relevant terms.
If you are looking to rank for a certain keyword, then you should include the keyword in the ALT text of any images for which it is relevant. For example, if you are trying to rank for “gluten free bread”, then you should include that phrase in the ALT text that accompanies your image of that bread. If your ALT text just says “bread”, that is far too general to be of any use to you.
It’s important not to confuse ALT text with the image title. The image title is what shows up in a pop-up box when the user’s mouse scrolls over the image. It’s useful, but it won’t help your search rankings in the way that ALT text can.
ALT text may not be exciting, but if you take time to put in those ALT text descriptions, it will help both visually impaired users of your website and Google discover what those images are and make good use of them. That’s worth a bit of effort, so take the time to check all the images on your website and make sure (a) that they all have ALT text, and (b) that this alt text is descriptive, relevant, clear, and contains the applicable keywords and keyword phrases.
Don’t thank me now – thank me later, when your search rankings improve.
Original post written for Webstruxure's blog.