AI Alt Text Writing: Making Images Accessible and SEO-Friendly

Alt text (alternative text) describes an image for screen readers and search engines — and it's one of the rare optimizations that serves accessibility and SEO simultaneously, with no trade-off. Good alt text is an accessibility obligation *and* the primary way Google understands what an image shows. Yet most sites either skip it or write useless placeholders like 'image'. Writing descriptive, keyword-aware alt text across a large library used to be tedious; AI vision models make it scalable. This article covers why alt text matters and how to do it well.

Why Alt Text Matters

• Accessibility: screen readers rely on alt text to convey images to visually impaired users — it's a genuine obligation, not just an SEO tactic
• Image SEO: alt text is the main signal Google uses to understand an image, so it directly affects whether images rank in image search
• Content context: relevant alt text reinforces your page's topical relevance, supporting overall rankings

AI Alt Text Best Practices

• Be descriptive: describe what's actually in the image. 'Bar chart showing SEO traffic growing from 10K to 50K monthly visits over 12 months' beats 'traffic chart'
• Include keywords naturally: if the image relates to your target keyword, work it in — but never stuff
• Keep it concise: roughly 125 characters or fewer for most images
• Skip decorative images: purely decorative images should have an empty alt attribute (alt="") so screen readers skip them

Accessibility First, SEO Second

The right mental model is accessibility-first: write alt text that would genuinely help someone who can't see the image understand it, and the SEO benefit follows naturally. Keyword-stuffed alt text fails both goals — it's useless to a screen-reader user and looks manipulative to Google. Describe accurately, include the keyword only when it's genuinely relevant, and you satisfy both audiences at once. Vincony's Alt Text Generator uses vision models to analyze each image and produce descriptive, SEO-aware alt text at 1 credit per batch — practical for optimizing an entire library, including the graphics you generate.