Alt Text for SEO: What It Is, Why It Matters, and How to Write It

Alt text for SEO might not be the most exciting task on your to-do list, but it plays a bigger role in helping your website rank than most people realise. Whether you’re running an online shop, writing blogs, or keeping your business site ticking along, adding meaningful alt text to your images can give your pages an extra boost in the eyes of Google and your visitors.

In this post, I’ll walk you through what alt text is, why it matters, how it helps with SEO, and how to write it properly.

What Is Alt Text for Images?

Alt text, short for alternative text, is a written description that you add to an image on your website. It appears when the image doesn’t load and is also used by screen readers to describe images to users who rely on assistive technology.

Alt text helps search engines understand what the image is about. This is important because search engines cannot actually see pictures. The importance of alt text lies in both accessibility and SEO. Originally designed to make the web more inclusive, it also gives your content a small but useful search advantage.

How Does Alt Text Help SEO?

You might be wondering if alt text actually helps with SEO or whether it is only useful for accessibility. The answer is that it supports both.

Google uses alt text to get a better understanding of what is shown in your images and how they relate to the rest of your content. When used properly, alt text can help reinforce the topic of your page. It can also give your images a chance to appear in Google Image Search, which opens up another traffic source.

Alt text supports keyword targeting in a subtle, natural way and helps create a better experience for users who rely on screen readers. While it will not suddenly send your site to the top of Google, it is a smart and simple way to strengthen your overall on-page SEO.

How to Write Alt Text That Actually Helps

Now that we have looked at why it matters, here is how to write alt text that works well for both users and search engines.

• Write a clear and honest description of what is in the image.
• Make sure the alt text is relevant to the surrounding content.
• Include keywords naturally, but only if they make sense in the sentence.
• Do not start with “image of” or “picture of” because screen readers already give that context.
• Keep the description brief and useful. Around 125 characters is usually enough.

Alt Text Examples: Good vs Not-So-Good

Here are a few alt text examples to show the difference between vague and helpful descriptions.

Too vague:
"SEO"
"Screenshot"
"Chart"

Much better:
"Google Search Console showing increase in impressions"
"Screenshot of WordPress alt text field with completed description"
"Bar chart comparing SEO traffic before and after optimisation"

The second set of examples gives more context to both search engines and users, which makes the content more useful.

FAQs About Alt Text and SEO

How long should alt text be?
One short sentence is usually enough. It should describe the image clearly without adding extra detail that does not help.

Can alt text be too long?
Yes, it can. Long alt text can overwhelm screen readers and confuse users. Keep it simple and straight to the point.

Does alt text really help with rankings?
Alt text is not a major ranking factor, but it plays a supporting role. It helps Google understand your content and gives your site a small competitive edge.

Is alt text important for small business websites?
Yes, it is. Many small business sites skip it entirely, so adding useful alt text can give you a quiet advantage over competitors.

Need Help with Alt Text for SEO (and the Rest of Your SEO Too)?

Alt text is more than just a box to tick. When it is written properly, it helps real people use your site and gives search engines more information about your content. For such a small task, it can have a real impact.

If you would rather focus on running your business and let someone else take care of the SEO side of things, my SEO Boost service includes alt text improvements. It also covers a range of other practical fixes to help your website perform better in search results. It is a straightforward way to get your site in better shape without having to deal with the details yourself.