Image Alt Checker
Articles, guides, and in-depth tips for the Image Alt Checker — everything you need to get the most out of it.
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Every Image Has Alt Text and the Page Is Still Unusable
Decorative Images Need alt="", Not Missing Alt — And Complex Images Need More Than One Line
Decorative images should have alt="" — not a missing alt attribute, which causes screen readers to announce the filename. Complex images (charts, diagrams, infographics) need both a concise alt text identifying the image type and a longer description of the data, via figcaption or aria-describedby. Here's the WCAG test for decorative, the three techniques for complex image descriptions, and why AI-generated alt text needs human review for technical and context-sensitive images.
When Accessibility and SEO Alt Text Goals Conflict — and How to Write Alt Text That Serves Both
Alt text for accessibility and alt text for SEO look identical in HTML — but the goals that inform them pull in different directions. Here's where they diverge: context-dependency (the same image needs different alt text in different contexts), keyword stuffing (which fails the "read it aloud" test), the functional images where SEO keyword inclusion is actively wrong, and the complex images where neither alt text alone nor SEO keywords capture enough information.
alt="" vs No Alt Attribute: Why This Tiny Difference Means "Skip This" or "Announce the Filename"
alt="" and a missing alt attribute look nearly identical in your HTML editor — one extra empty-quotes substring — but to a screen reader, they mean opposite things: alt="" says "decorative, skip this," while missing alt often triggers an announcement of the filename itself. Here's the practical difference, why every img tag should have an alt attribute (even if empty), and the special case where alt="" on an image-as-link removes the link's accessible name entirely.
Alt Text and the Law: How WCAG 1.1.1 Became Central to ADA Lawsuits and the European Accessibility Act
Missing alt text has become a commonly-cited basis for ADA website accessibility lawsuits in the US, with thousands filed annually affecting businesses of all sizes — and the EU's European Accessibility Act adds direct legislative requirements referencing the same WCAG standards. Here's how alt text fits into WCAG 1.1.1, the empty-vs-missing alt attribute distinction that audits often miss, and why good SEO alt text practices overlap substantially with legal compliance.
Image SEO Beyond Alt Text: File Naming, WebP/AVIF, Schema, and Image Sitemaps
Google Images accounts for 22% of all web searches and most sites ignore its ranking signals entirely. Here's how image file naming, WebP/AVIF formats and Core Web Vitals, lazy loading and Googlebot, ImageObject schema, and image sitemaps all contribute to image search visibility.
Writing Alt Text That Works for Both SEO and Accessibility
Alt text that works for both screen readers and SEO follows specific principles: contextual relevance, appropriate keyword inclusion without stuffing, and different approaches for different image types. Here's the craft behind writing alt text that does both jobs well.
Image Alt Checker — Find Every Missing Alt Text on Any Web Page
Learn what image alt text does for SEO and accessibility, what good alt text looks like, and how to use a free image alt checker to find all missing or inadequate alt text on any web page.
