What Is Alt Text For Images: Boost SEO & Accessibility.

Alt text is a short, written description of an image on a webpage that serves two main purposes: making your site accessible to visually impaired users and helping search engines like Google understand your content. In the UK, getting it wrong isn’t a minor detail. It can affect access for 2.2 million people with visual impairments, weaken your visibility in search, and create compliance risk under the Equality Act 2010.

If you’ve recently launched a website, this is one of the easiest gaps to miss. The photos look sharp, your branding is polished, and your pages load nicely on mobile. But if your images don’t have proper alt text, a screen reader user may miss key information, Google gets less context about your content, and important actions like enquiry buttons inside images can become harder to use.

That matters for any business, but it matters even more for small businesses in Scotland competing locally. A trades firm in Dalkeith, an online retailer in Midlothian, or a professional service in Edinburgh doesn’t need more vague “SEO tips”. It needs the basics done properly. Alt text sits in that category. It’s small, technical, and directly tied to visibility, usability, and trust.

An Introduction to Alt Text for Images

Most business owners first meet alt text while uploading photos into WordPress, Shopify, or a page builder. There’s usually a field labelled “Alt text” or “Alternative text”, and it’s tempting to skip it because nothing visibly changes on the page. That’s exactly why it gets ignored.

Alt text is the invisible layer that tells software what an image means. If someone uses a screen reader, the device reads that description aloud. If search engines crawl your site, they use that text to better understand the image and the page around it. If an image fails to load, alt text may appear in its place.

What alt text actually does

For a small business site, alt text usually serves three jobs:

• Accessibility for real users. It helps people who can’t see the image understand what’s there and whether it matters.
• SEO support for image and page relevance. It gives Google more context about products, services, locations, and page intent.
• Legal protection in the UK. Missing or poor alt text can contribute to accessibility failures under UK law.

That last point often surprises people. Under the Equality Act 2010, failure to provide adequate alt text can be a breach of accessibility duties, which matters because disabled users represent a large part of the market and accessibility failures carry real business cost. If you want a broader look at how content structure supports website performance, this guide to well-designed content pages is worth reading alongside image accessibility.

Why this matters more than owners think

When people search for what is alt text for images, they’re often expecting a technical definition. The useful answer is more practical than that. Alt text helps a customer understand your site, helps Google classify your visuals, and helps your business avoid avoidable mistakes.

Alt text isn’t admin. It’s part of how your website communicates.

That’s why good websites don’t treat it as an afterthought. They treat it as part of publishing the page properly.

Why Alt Text is Crucial for Your Website's Success

A lot of website tasks feel optional. Alt text isn’t one of them. It sits at the point where accessibility, search visibility, and business performance overlap.

Accessibility is the first job

Think of alt text as a digital tour guide. A sighted visitor looks at a product photo, a team image, or a service icon and understands the point instantly. A screen reader user needs that same meaning delivered in words.

Under the UK’s Equality Act 2010, failure to provide adequate alt text can be a breach of accessibility duties. That affects a substantial market because there are approximately 2.2 million people with visual impairments in the UK, and digital exclusion carries an estimated £17.1 billion annual economic cost, as outlined in this alt text guidance from Nielsen Norman Group .

That isn’t just a public sector issue. If your site sells, books, quotes, or informs, accessibility directly affects whether a customer can use it.

SEO works better when images are understandable

Google can read surrounding text, headings, and structured content. It still benefits from a clear description of the image itself. That’s where alt text acts like a label in Google’s filing cabinet. It helps search engines connect the image to the page topic, the service area, and the user’s search intent.

For local businesses, that matters more than many owners realise. A kitchen fitter showing completed installations in Midlothian, a salon with treatment photos, or a retailer with product shots all rely on images to sell trust. If those images are unlabeled, you’re leaving context on the table.

If improving search performance is one of your goals, this guide on how to improve Google search rankings pairs well with a proper alt text review.

It affects conversions, not just compliance

Accessibility and SEO are often discussed as separate topics. On a real business website, they feed the same outcome. Better clarity means more people can understand the page, trust what they see, and take action.

A few examples make that obvious:

The second version helps the user and gives the page stronger context.

For a wider accessibility perspective beyond images alone, Web Application Developments on accessibility gives a useful overview of inclusive digital practice. It’s US-focused in framing, but the practical thinking translates well to UK businesses trying to serve every customer properly.

If an image helps a buyer decide, compare, trust, or click, it needs alt text that does the same job in words.

That’s the business case in one line.

How to Write Perfect Alt Text Every Time

Writing good alt text is less about sounding clever and more about making decisions. You’re deciding what matters in the image, what the user needs from it, and what can be left out.

Start with the purpose, not the pixels

The same image can need different alt text depending on where it appears.

A product image on a category page should usually help someone identify the item quickly. A linked image should tell the user what happens if they click. A decorative flourish next to a heading often needs no descriptive alt text at all.

Practical rule: describe the image in context, not in isolation.

That one rule fixes most weak alt text.

Keep it short and specific

WCAG guidance commonly recommends keeping alt text under roughly 100 to 125 characters to avoid screen reader overload. For commercial pages, functional wording such as “Red wool scarf, £45, handmade in Midlothian” can also support image relevance and was linked to a 20% uplift in local image search traffic in the source material used here from this alt text guide .

Short doesn’t mean vague. It means focused.

Here’s the test I use: if someone heard the alt text once, would they understand why the image is on the page?

Good, better, best examples

Product images

• Good: “Scarf”
• Better: “Red wool scarf”
• Best: “Red wool scarf, £45, handmade in Midlothian”

The best version adds the details a buyer cares about.

Service images

• Good: “Plumber”
• Better: “Plumber fixing kitchen sink”
• Best: “Emergency plumber repairing kitchen sink in Dalkeith home”

This works because it reflects service type, task, and local relevance without sounding stuffed.

Linked call-to-action images

• Good: “Button”
• Better: “Book now”
• Best: “Book a bathroom fitting consultation”

When an image is clickable, the alt text should describe the destination or action.

What to include and what to skip

A useful way to decide is this quick checklist:

• Include the key subject. Name the product, person, place, or action.
• Include commercial detail when it matters. Price, material, size, or location can be helpful on retail and service pages.
• Skip filler phrases. You don’t need “image of” or “picture of”.
• Skip details nobody needs. Background colours, lighting, and artistic flourishes usually don’t help.
• Skip repetition. If the adjacent text already says exactly the same thing, don’t echo it pointlessly.

For teams refining all the on-page details around search presentation, this article on how to write meta descriptions complements the same principle. Write for the user first, but keep the search context clear.

Know when to use empty alt text

Not every image should be described. Decorative graphics, background flourishes, repeated visual separators, and purely aesthetic stock images often shouldn’t add noise for screen reader users.

Use an empty alt attribute like this:

alt=""

That tells assistive technology the image can be ignored.

A simple decision rule works well:

That’s where many websites go wrong. They either describe everything, which becomes exhausting, or they describe nothing, which strips meaning from the page.

Common Alt Text Mistakes to Avoid

Most alt text problems don’t come from bad intentions. They come from rushed uploads, copied templates, and people treating the field like a place to dump keywords.

Data cited for this topic shows 68% of UK websites fail basic WCAG alt text requirements, and for service businesses, missing alt text on critical button images can cause up to a 25% form abandonment rate, directly affecting lead capture, according to this discussion of image alt text mistakes .

Stuffing keywords into the alt field

A common assumption is that more keywords must mean better SEO. It doesn’t. Alt text like “plumber Dalkeith plumber Midlothian emergency plumber boiler repair” is poor for users and poor for search quality.

Fix: Write one natural description that matches the image and the page.

Leaving important images blank

Blank alt text is correct for decorative visuals. It’s wrong for product images, logos, charts, linked banners, and image buttons. If a user needs that image to understand or use the page, leaving it blank creates friction.

Fix: Add alt text to every meaningful image and every image that acts as a link or button.

Writing far too much

Some site owners swing the other way and write miniature essays. That overwhelms screen reader users and usually includes detail that doesn’t help anyone take action.

Fix: Keep the description focused on the image’s function and the most important identifying details.

Using file names or generic labels

If your CMS pulls in “IMG_4729.jpg” or “team-photo-final-2” as alt text, that’s not accessibility. It’s clutter. The same goes for labels like “image”, “graphic”, or “photo”.

Fix: Replace file names with plain-language descriptions a customer could understand immediately.

Bad alt text usually fails in one of two ways. It says too little to be useful, or too much to be usable.

If you audit a website and fix only those four issues, the improvement is often immediate.

A Practical Guide to Adding Alt Text to Your Website

Knowing what alt text should say is one thing. Adding it properly inside your platform is the part that gets pages fixed.

This matters now because the European Accessibility Act is due to be transposed into UK law by 28 June 2025, expanding requirements to private e-commerce, and non-compliant sites risk 15 to 20% traffic loss from Google’s increasing emphasis on accessibility signals, based on the verified source material for this topic. That’s why this work shouldn’t sit in a “do later” list.

Adding alt text in WordPress

WordPress makes this straightforward, but many sites still miss it because images are uploaded in bulk.

1. Open Media and select the image.
2. Find the Alternative Text field in the attachment details.
3. Write the description based on the image’s purpose on the page.
4. Save it before inserting the image.
5. If the image is already on the page, check the block settings to confirm the alt text is correct there too.

A practical tip: don’t rely on the title field. The alt field is separate.

Adding alt text in Shopify

Shopify hides this slightly more than WordPress, so some store owners skip it.

1. Open the product, collection, or page where the image is used.
2. Click the image.
3. Choose the option to edit the image details or alt text.
4. Add a concise description that helps identify the product or the action.
5. Save the change and review the front-end page.

For product-heavy stores, it helps to set a simple standard. Include the product type, key distinguishing feature, and any detail that helps the buyer choose.

Adding alt text in raw HTML

On a custom-coded site, the alt attribute sits inside the image tag itself.

<img src="red-wool-scarf.jpg" alt="Red wool scarf, handmade in Midlothian">

Each part does something specific:

• src points to the image file.
• alt provides the text alternative a screen reader can read.
• If the image is decorative, use alt="" instead of leaving it out.

That last detail matters. Omitting the alt attribute altogether is not the same as intentionally marking an image decorative.

One implementation habit that saves time

Before uploading large batches of visuals, prepare the image file dimensions and naming properly first. It makes the whole content process cleaner, especially if you’re updating products or portfolio items at scale. This guide on sizing images for websites is useful if your media library is currently a mess.

Write alt text when you upload the image, not months later during a cleanup job.

That’s when context is still obvious, and the quality is better.

Your Essential Alt Text Audit Checklist

A lot of accessibility advice stays theoretical. The easier approach is to open your own site and review it page by page with a short checklist.

The UK Government’s own monitoring reported 68% of public sector websites were non-compliant with alt text requirements, and the Equality and Human Rights Commission noted a 25% rise in web accessibility lawsuits from 2024 to 2025 for private SMEs in Scotland, according to the verified source assigned to this topic. That doesn’t mean every small business is about to face legal action. It does mean ignoring image accessibility is a clear risk.

Questions to ask as you audit

• Does every meaningful image have alt text. Check products, team photos, logos, charts, portfolio images, and service visuals.
• Have decorative images been given alt="". Background flourishes and non-essential design graphics shouldn’t create noise.
• Do linked images describe the action or destination. A clickable banner should tell users what happens next.
• Is the alt text concise. Remove filler, duplicated wording, and obvious visual detail that doesn’t help.
• Does the wording match the page context. The same image may need different alt text on a category page than on a product page.
• Are any file names showing through. If you see text like IMG_2048 or final-banner-v2, rewrite it.
• Do image buttons and enquiry graphics have useful alt text. These often get missed and can hurt lead generation.
• Are charts or diagrams explained properly. If an image carries data or process information, the user needs an equivalent explanation.
• Have you tested a few key pages manually. Don’t just trust the CMS field. Open the page and inspect important images.

Where to start if your site is large

Don’t try to fix every image on the site in one sitting. Prioritise:

1. Homepage
2. Service pages
3. Product and category pages
4. Contact and booking journeys
5. Blog posts that attract search traffic

If you want a wider review process beyond images alone, this website audit checklist is a solid companion.

Small technical details often decide whether a site feels polished or amateur. Alt text is one of those details. It shapes how accessible your site is, how clearly search engines understand it, and how professionally your business presents itself online in the UK.