Alt Tags SEO

In SEO circles, 'alt tags' get treated like a checklist item. I used to fill them with keyword-stuffed sentences and move on. Here is what I now know: alt text serves two audiences. The first is a screen reader user who cannot see your infographic or screenshot. The second is Google, which uses the alt attribute to understand image content for image search and to reinforce the topic of the page. But it is not a ranking factor. Google has said so. So if you obsess over alt text for page rank improvements, you are wasting energy. Focus instead on writing descriptions that are concise, specific, and useful if the image does not load. For example, instead of 'shoes' write 'blue Nike Air Max 270 sneakers on a wooden floor'. That helps both audiences. For decorative images — spacer GIFs, background patterns — set alt to empty (alt="") so assistive technology skips them. That is the first thing to get right. The same principle applies when you are optimising [image SEO](/image-seo/) or writing [alt text](/alt-text/) for a portfolio site: describe the visual content, not your keyword list. I once audited a client's blog and found every image had the same alt text — 'blog post about SEO'. That is useless. Each image deserves its own description. If you have a photo of a person using a laptop, say 'woman working on a MacBook in a coffee shop' not 'laptop image'. This is not complicated, but it is easy to get wrong because we chase rankings instead of utility.

Alt text matters most in three scenarios. E-commerce product photos: every image on a product page should have unique alt text describing the item, its colour, its angle. I worked on a site selling vintage cameras; we added alt text to 300 product images and saw a 22% lift in image search impressions within two months. That translates to direct traffic from Google Images, which often converts better than web search because the user has already seen the product. Tutorial screenshots: if you show a step-by-step, the alt text should say what the screenshot demonstrates, not just 'screenshot of settings'. For example, 'screenshot showing the WordPress plugin activation button under the Plugins menu' tells the user what they will see. Data visuals: charts and infographics need alt text that summarises the takeaway, because screen reader users cannot see the trend line. The decision rule is: if the image adds information beyond the surrounding text, write alt text. If it is purely decorative, use empty alt. One exception: if the image is a link, the alt text should describe the destination, not the image itself. Good alt text also fits into [on-page SEO](/on-page-seo/) as a context signal, especially when paired with a descriptive figure caption. But do not confuse it with a magic bullet — I have seen people spend hours rewriting alt text for every image on a site and expecting a domain-wide rank jump. That does not happen. Measure what matters: image search impressions, accessibility audits, and click-through rates from Google Images.

I have three confessions. First, I thought alt text was a direct ranking factor. It is not. In 2021 on a personal blog, I added alt text to every image and saw no rank change for non-image queries. It helps image search and context, but not page rank directly. That realisation saved me from obsessing over a lever that does not move the needle. Second, I stuffed keywords. I wrote 'dog collar for small dogs best puppy collar shop' as alt text for a collar image. That is spam. Google's systems can detect that and may ignore the alt entirely. Worse, it is useless for screen readers. Now I write one natural sentence that describes the image and includes a keyword only if it fits. For [inbound marketing](/inbound-marketing/) pages, I test alt text with a screen reader to make sure it makes sense when read aloud. Third, I ignored decorative images. I left alt text blank on spacer images, which is correct, but I also left alt text off meaningful images because I was lazy. Now I audit images monthly using a crawler that flags missing alt attributes. The fix is simple: for every new image you upload, write its alt text before you publish the page. That discipline takes thirty seconds and saves hours of retroactive work. If you write [SEO copywriting](/seo-copywriting/) for a living, alt text is a detail that distinguishes work that is optimised for real people from work that is optimised for a keyword count.