Alt text is a written description of an image that serves two purposes: it is read by screen readers for visually impaired users, and it helps search engines understand what an image depicts. Most Melbourne business websites either ignore alt text entirely or fill it with keyword-stuffed descriptions that help neither users nor Google. Correct alt text is a core component of both on-page SEO and accessibility — here is how to do it correctly for your SEO strategy.
| Image Alt Text Best Practice | Key Takeaway |
|---|---|
| Describe the Image Accurately | Explain what the image shows and its purpose in the page context. |
| Use Keywords Naturally | Include relevant keywords only when they accurately describe the image. |
| Keep Alt Text Concise | Focus on essential details; 125 characters is a guideline, not a strict limit. |
| Avoid Redundant Phrases | Start with the description instead of “image of” or “photo of”. |
| Use Empty Alt Text for Decorative Images | Use alt="" for images that convey no meaningful information or function. |
| Adapt Alt Text to Image Types | Write appropriate descriptions for product photos, logos, charts and infographics. |
| Audit Existing Images | Check for missing, inaccurate and irrelevant alt text across important pages. |
| Check Links and Complex Images | Describe image-link functionality and provide detailed text alternatives for complex graphics when needed. |
| Verify and Monitor Changes | Check the published HTML and review image search performance where relevant. |
1. Describe what the image actually shows
The most important rule is that alt text should accurately describe the image. If the image shows a Melbourne dentist examining a patient's teeth, the alt text should say something like "dentist examining patient's teeth in Melbourne clinic" — not "dentist Melbourne affordable dental services cosmetic dentistry".
Screen reader users rely on alt text to understand what an image communicates. If your alt text does not describe the image accurately, you are failing your visually impaired visitors. Google also understands what images depict with increasing accuracy and notices when alt text is inconsistent with the image content.
2. Include relevant keywords naturally
Alt text is an opportunity to include keywords that are relevant to both the image and the page it sits on. The key is that the keyword should be included because it accurately describes the image, not forced in regardless of the content.
A photo of your plumbing team at work in a Melbourne home naturally warrants alt text like "plumbing team repairing kitchen pipes in Melbourne home" — this includes relevant terms because they genuinely describe the image.
3. Keep it concise
Alt text should be long enough to describe the image clearly but not so long that it becomes a paragraph. A general guideline is 125 characters or fewer — roughly one to two descriptive sentences. Screen readers typically cut off alt text after this point.
4. Do not start with "image of" or "photo of"
Screen readers already announce that the element is an image before reading the alt text. Starting your alt text with "Image of..." or "Photo of..." is redundant. Begin with the description directly: "Dentist examining patient's teeth" rather than "Image of a dentist examining a patient's teeth".
5. Use empty alt text for decorative images
Not every image needs alt text. Decorative images — background patterns, dividers, abstract design elements that carry no informational content — should have empty alt text (alt="") rather than descriptive text. This tells screen readers to skip the image entirely, which improves the listening experience for visually impaired users.
Adding descriptive alt text to purely decorative images is actually considered an accessibility error because it creates noise for screen reader users without adding meaning.
Frequently Asked Questions
Does alt text help SEO?
Yes. Alt text helps Google understand the subject of an image alongside the page content and other image signals. It can support image search visibility, but it does not guarantee higher rankings.
How long should image alt text be?
Write the shortest description that communicates the image's essential information or purpose. Around 125 characters can be a useful informal guideline, but it is not a universal technical limit. Complex images may need a more detailed explanation elsewhere on the page.
Should every image have alt text?
Informative images need meaningful text alternatives. Decorative images should generally use an empty alt="" attribute, while images used as links or buttons should communicate their function when that information is not already provided by accompanying text.
Can you use keywords in image alt text?
Yes, when the keywords accurately describe the image and fit naturally into the sentence. Avoid adding keywords simply to influence rankings, particularly when they do not match the image.
How do you check if an image has alt text?
You can inspect the image's HTML, review its alternative text field in your content management system or use a website crawler and accessibility testing tool. Remember to check whether existing descriptions are meaningful, not just whether an attribute is present.
Final Thoughts
Image alt text is a small but important part of building an accessible, well-optimized website. By describing images accurately, using keywords naturally, keeping descriptions concise and providing empty alt attributes for decorative images, you can make your content more useful for visitors and easier for search engines to interpret.
For businesses investing in SEO, reviewing image alt text should be part of the wider process of improving on-page content and website accessibility. Regular audits help identify missing descriptions, correct misleading text and maintain a consistent standard as the website grows.
Amin leads SEO strategy at Web Like Web, specialising in on-page, off-page and technical SEO. He has driven organic growth for hundreds of Australian businesses across competitive industries.
