Image SEO is often reduced to one instruction: put a keyword in the alt text. That approach misunderstands both accessibility and optimisation. Alternative text exists to provide a useful text alternative when an informative image cannot be seen, while search performance also depends on factors such as image relevance, surrounding content, file delivery and page speed. Good optimisation starts by deciding what the image contributes to the page.
Understand the purpose of alt text
Alt text describes the meaningful content or function of an image for situations where the visual itself is unavailable, including use with assistive technology. The appropriate wording depends on why the image is present.
An informative photograph may need a concise description of what matters in context. A functional image used as a control needs text that communicates its function. Decorative images generally should not force irrelevant descriptions into the reading experience.
Describe the image in its page context
The same image could require different wording depending on how it is used. A photograph illustrating a product detail should describe the detail that matters, while an image supporting an article may need a different emphasis.
Write for somebody who needs the information conveyed by the image. Avoid introductory filler such as repeatedly stating that something is an image when the context already establishes that. Concision is useful, but completeness matters more than hitting an arbitrary character count.
Do not turn alt attributes into keyword lists
If a relevant search term naturally describes the image, it may appear in the alt text. That is different from inserting several keyword variants into every image on the page.
Keyword-stuffed descriptions are poor accessibility and weak editorial practice. Search relevance should come from the page as a whole: its subject, headings, copy, internal links and genuinely relevant media all contribute context.
Use sensible filenames before upload
A descriptive filename can make media libraries easier to manage and gives the asset a clearer identity than a camera-generated string. Rename important images before publishing where that fits the workflow.
Keep filenames straightforward and descriptive rather than packing them with repeated terms. Changing filenames across an established site solely for SEO can create unnecessary work and broken references if the migration is not handled carefully.
Reduce image weight without damaging usefulness
Large image files can slow pages substantially, particularly on mobile connections. Resize assets to dimensions appropriate for their display and use efficient formats and compression suited to the type of image.
Responsive image techniques can allow browsers to choose an appropriate source for the visitor's screen. This avoids forcing a small device to retrieve a much larger asset than it needs.
Load images according to their importance
Lazy loading can reduce initial work by delaying images further down the page until they are needed. It should be applied thoughtfully rather than automatically to every asset.
An important image visible immediately may need different loading treatment from a gallery near the bottom. Optimisation should support the actual viewing sequence and avoid creating delays for content the visitor expects to see straight away.
Keep surrounding content relevant
Search systems do not interpret an image in isolation. Captions, headings and nearby copy can provide context, as can the overall subject of the page.
Place images where they genuinely support the information being discussed. Adding unrelated stock imagery and optimising its alt text will not make a page more authoritative. Useful media should clarify, demonstrate or help a visitor make a decision.
Audit images as part of normal SEO maintenance
Website changes can introduce missing alt attributes, oversized uploads and broken image references over time. Periodic crawling and performance checks can identify patterns worth fixing, particularly on templates and high-traffic pages.
Do not judge an image audit only by whether every alt attribute contains text. Some images are decorative, and quality depends on context. Review important examples manually alongside automated reports.
Optimising images for SEO with alt text is therefore a combined accessibility, editorial and performance task. Describe meaningful visuals accurately, keep decorative media from creating noise, deliver files efficiently and place images where they support the page. When those elements work together, image optimisation improves the experience without turning alt text into another place for keyword stuffing.