When Google crawls your website, it reads text. It reads headings, paragraphs, links, page titles, and metadata. What it cannot do is look at a photo and understand what’s in it the way a human does.
So when Google’s crawler encounters an image on your website, it looks for two things: the file name and the alt tag. If those are missing or meaningless, Google moves on with no idea what that image contains or why it’s there. For a search engine trying to understand and rank your page, that’s a wasted opportunity every single time.
Most Australian business websites are full of images named IMG_4872.jpg uploaded with no alt tag in sight. The business owner spent good money on photos. The photographer delivered great work. And then it was uploaded in a way that made it completely invisible to search engines and screen readers alike.
Alt text (short for alternative text) is a written description of an image that sits in the HTML code of your page. Visitors to your website don’t see it unless the image fails to load. But three very important audiences do see it.
Search engines use alt text to understand what an image shows and to index it in Google Image Search. A well-written alt tag tells Google not just what the image is, but reinforces the topic of the page it sits on.
Screen readers read alt text aloud to users who are blind or have low vision. Without it, a screen reader announces “image” and moves on, leaving those users with no context. This is an accessibility requirement under WCAG 2.2 guidelines, and increasingly a legal consideration for Australian businesses.
AI crawlers use alt text and image metadata as part of their understanding of your page’s authority and relevance. As Google’s AI Mode and AI Overviews become the dominant search experience, clear, accurate image descriptions contribute to how confidently AI can cite and recommend your business.
These two fields are often confused, so let’s separate them clearly.
The image title is a tooltip that appears when a user hovers their cursor over an image on desktop. It has minimal direct SEO value on its own, but it does contribute to overall page context and user experience. In WordPress, it’s the “Title” field in the media library.
The alt tag is the description of the image. This is the field that carries genuine SEO weight and accessibility function. In WordPress, it’s the “Alt Text” field in the media library or the image block settings. This is the one most businesses leave blank.
The file name is technically separate again, but it matters too. Google reads the file name before it even gets to the alt tag. An image uploaded as sunshine-coast-wedding-photographer-ceremony.jpg tells Google something useful before the alt tag is even read. An image uploaded as DSC_0047.jpg tells Google nothing.
Good alt text is descriptive, specific, and natural. It doesn’t keyword-stuff. It doesn’t repeat your business name ten times. It just accurately describes what’s in the image in plain language, with the relevant context your page is about woven in naturally.
Here are some examples of the difference between poor and good alt text:
Poor: alt="" (blank)
Poor: alt="image1"
Poor: alt="plumber plumbing plumber Brisbane plumbing services" (keyword stuffing)
Good: alt="Licensed plumber replacing bathroom tap in a Brisbane home"
Poor: alt="food"
Good: alt="Smashed avocado on sourdough with poached eggs, served at our Caloundra cafe"
Poor: alt="team"
Good: alt="The Gravity Projex team at our Sunshine Coast office"
The goal is to write what a person would say if they were describing the image to someone who couldn’t see it. That description, done well, is naturally SEO-friendly without trying to be.
Two shifts have made image optimisation more important now than at any previous point.
The first is Google Image Search. It drives a significant volume of discovery traffic, particularly for product-based, food, tourism, and lifestyle businesses. Images with strong alt text and descriptive file names rank in Google Images and drive clicks to your website. Images without them don’t appear at all.
The second is the rise of AI search. As we covered in our piece on Google AI Mode, the signals AI systems use to understand and cite your business extend to every element of your page, including images. A page with ten well-described images sends stronger topical relevance signals than an identical page with ten unnamed, undescribed files.
Google’s AI systems are also increasingly capable of reading image content directly, but they still weight alt text heavily because it represents intentional, explicit information provided by the page author. It’s a direct signal, not an inference.
Accessibility legislation is also tightening. The Australian Human Rights Commission has been clear that web accessibility applies under the Disability Discrimination Act, and blank alt tags on informative images are a common point of failure in accessibility audits.
If your website runs on WordPress, fixing your image alt tags is straightforward. Here’s how to do it.
Go to Media in your WordPress dashboard and select Library. Click on any image. In the panel that opens on the right, you’ll see fields for Title, Caption, Alt Text, and Description. The Alt Text field is the one you need to fill in. Write a clear, natural description of what the image shows and what page or service it relates to. Save and move to the next image.
If you have a large library, work through the images on your most important pages first: your homepage, your main services or product pages, and your about page.
When you upload a new image via the Media Library or add one directly to a page, fill in the Alt Text field before you click Insert. Make it a habit. It takes 10 seconds and it pays dividends every time that page is crawled.
Before you drag an image into WordPress, rename the file on your computer to something descriptive. Use hyphens between words, keep it lowercase, and make it specific. “sunshine-coast-web-designer-portfolio.jpg” is correct. “Screenshot 2026-04-11 at 3.22pm.png” is not.
Once an image is uploaded to WordPress, renaming it requires a plugin or manual file management. It’s much easier to get the name right before it goes in.
If you want to find every image on your site that’s missing alt text, the free plugin SEO Framework or Rank Math will flag these in their site audits. Alternatively, running your URL through Google Search Console or a tool like Screaming Frog will produce a list of all images and their alt attributes so you can identify the gaps quickly.
Not every image needs an alt tag. Purely decorative images — backgrounds, dividers, abstract design elements that carry no informational value — should have an empty alt attribute rather than a description. That looks like this in HTML: alt=""
An empty alt attribute tells screen readers and search engines to skip the image intentionally. This is correct behaviour. What you should never do is leave the alt attribute out entirely, because that tells screen readers to read the file name, which is usually useless and sometimes confusing.
The rule of thumb: if the image contains information (a product, a person, a location, a service being performed), write descriptive alt text. If it’s purely visual decoration with no content value, use alt="".
alt="" for purely decorative images.This is the kind of fix that doesn’t feel glamorous, which is exactly why most businesses never do it. But SEO is built on dozens of small signals that add up. Alt tags are one of the cleaner, more controllable signals you have direct access to. Filling them in correctly costs you nothing except a few minutes, and it makes your website more visible to search engines, more accessible to users with disabilities, and more legible to the AI systems that are increasingly deciding who gets found online.
If your website has hundreds of images sitting untagged and unnamed, that’s not a disaster. It’s just an opportunity you haven’t taken yet.
Want us to audit your site and flag exactly where you’re losing ground on the basics?
SEO has changed significantly in the past two years. Here's what actually matters for Queensland small businesses trying to get…
Read more
Stay ahead of the curve with these emerging search engine optimisation strategies that are reshaping how businesses get found online.
Read more
Google just announced this is the biggest change to Search in 25 years. AI Mode has passed one billion monthly…
Read moreLet's discuss how Gravity Projex can help accelerate your business growth.
Launch Projex