Images missing alt text: SEO, accessibility, and AI impact
Alt text describes an image to people using screen readers and to crawlers that cannot see images. Every meaningful image needs descriptive alt; decorative images need alt="" (empty but present).
Alt text describes an image to people using screen readers and to crawlers that cannot see images. Every meaningful image needs descriptive alt; decorative images need alt="" (empty but present). The alt attribute on an <img> tag (alt="description here") provides a text alternative for the image. It is read by screen readers, used by Google Images to rank the image, and increasingly extracted by AI answer engines as context about the surrounding content.
Last updated·
What it is
The alt attribute on an <img> tag (alt="description here") provides a text alternative for the image. It is read by screen readers, used by Google Images to rank the image, and increasingly extracted by AI answer engines as context about the surrounding content.
Why it matters
Missing alt is the #1 accessibility violation in WCAG audits. It also means the image is invisible to Google Images (a substantial share of visual-search traffic), and AI engines that summarise your page may misinterpret what is shown. For e-commerce, missing product-image alt is direct lost revenue.
How to fix it
- Describe what is in the image, briefly. Aim for 5–15 words. "Red Adidas Ultraboost running shoe, side view" not "shoe.jpg" or "Adidas running shoe Ultraboost red sneaker athletic footwear".
- Use alt="" for purely decorative images. Background flourishes, dividers, and decorative icons should have an EMPTY alt attribute — not a missing one. Screen readers correctly skip alt="".
- Never stuff keywords. alt="best cheap running shoes for men women athletic" is a flag for Google's spam systems. Describe the image, do not keyword-stuff it.
- For complex images (charts, infographics) provide context nearby. A 15-word alt cannot describe a chart. Use a short alt plus a longer text description in surrounding paragraphs or a <figcaption>.
Authoritative sources
- Image SEO best practices — Google Search Central
- WCAG 2.1 — Non-text Content (1.1.1) — W3C WAI
- An alt Decision Tree — W3C WAI
- Google Search Central documentation — Google
- Schema.org vocabulary — schema.org
- SEO Starter Guide — Google Search Central
- MDN — HTML meta and link elements — Mozilla MDN