The Ideal Length for Alt Descriptions

For most images, write alt text between roughly 50 and 125 characters. That is long enough to describe the subject, context and any meaningful detail, and short enough that assistive technology users are not forced to sit through a paragraph before reaching the next element. Screen readers do not enforce a hard cut-off, but many older tools and some browsers truncate around 125 characters, and listeners lose patience well before that. If an image genuinely requires more explanation, such as a complex chart or infographic, keep the alt attribute concise and place the full explanation in visible page text or a long description nearby.

How AAMAX.CO Improves Image SEO and Accessibility

Image optimisation is one of the most neglected wins in on-page work, which is why we build it into every engagement at AAMAX.CO. As a full service digital marketing company offering Web Development, Digital Marketing and SEO Services worldwide, our SEO services include auditing every image on your site for missing or duplicated alt text, oversized files, wrong formats, missing dimensions and lazy loading errors, then fixing them at the template level so the problem does not return. The result is a site that is faster, more accessible, more likely to appear in image search, and easier for search engines to understand. If your site is image heavy, this work usually pays back quickly.

Why Alt Text Exists and Who It Serves First

Alt text was created for accessibility. It gives people using screen readers, and anyone whose images fail to load, an equivalent understanding of what the image conveys. Search engines then use it as a secondary signal to interpret image content and page topic. Keeping that order of priority in mind solves most alt text debates: write for the human who cannot see the image, and the SEO benefit follows naturally. Text written primarily to game rankings almost always reads badly aloud, which is a reliable sign it is wrong.

What to Include in a Good Alt Description

Describe the subject, the action and the relevant context in a natural sentence fragment. Include a keyword only when it genuinely belongs. Avoid starting with phrases such as image of or picture of, because assistive technology already announces that it is an image. Skip the word graphic, drop redundant branding on every single asset, and do not repeat the caption verbatim if the caption is already visible. For product photography, mention the product name, colour, material or angle, since those attributes are exactly what image searchers query.

When Alt Text Should Be Empty

Purely decorative images should carry an empty alt attribute rather than a description. Background flourishes, spacers, decorative dividers and icons that sit beside text already conveying the same meaning all fall into this category. An empty attribute tells screen readers to skip the element, which improves the listening experience. Removing the attribute entirely is not the same thing: some tools will then read the file name aloud, which is far worse. Likewise, if an image is wrapped in a link, the alt text should describe the link destination rather than the picture.

Common Alt Text Mistakes

Keyword stuffing remains the most damaging error, both because it degrades accessibility and because it looks manipulative. Duplicating identical alt text across dozens of gallery images is another, since it tells search engines nothing distinct. Leaving alt text as an auto-generated file name, writing overly long paragraphs, describing colour and layout instead of meaning, and forgetting alt text entirely on hero images are all frequent findings in audits. On large sites these problems are usually systemic and fixable in one template change.

Alt Text Is Only Part of Image SEO

To rank in image results and keep pages fast, pair good alt text with descriptive, hyphenated file names, modern formats such as WebP or AVIF, responsive sizes with correct width and height attributes to prevent layout shift, lazy loading below the fold, and an image sitemap for large libraries. Surrounding text matters too: search engines infer meaning from captions, nearby headings and paragraph context. An image placed inside a relevant, well-written section will outrank an identical file dropped into a thin page.

Scaling Alt Text Across Thousands of Images

For catalogues, generate alt text from structured product data using templates that combine name, key attribute, variant and use case so each output is unique. Reserve handwritten descriptions for hero images, editorial photography, charts and anything used in marketing campaigns. Run a quarterly crawl to catch new images shipped without alt text, and add a required alt field to your content management workflow so the gap never reopens. If you use AI to draft descriptions, always review them, because generated text frequently describes the wrong subject or invents detail.

Alt Text in an AI Powered Search Landscape

As AI systems summarise pages and answer visual queries, accurate image descriptions help those systems represent your content correctly. This is why image optimisation increasingly overlaps with GEO services and with broader digital marketing work: the same clean, descriptive metadata that serves screen readers also helps machines cite you accurately.

Quick Reference

Target 50 to 125 characters, describe meaning rather than appearance, include keywords only where natural, use empty alt for decoration, describe destinations for linked images, never start with image of, keep every description unique, and audit regularly. Get those habits right and your images will quietly contribute traffic, accessibility compliance and better page performance all at once.