Image Alt Text Checker

Why alt text matters for SEO

Alt text (alternative text) is an HTML attribute that describes the content of an image. Search engines cannot see images the way humans do, so they rely on alt text to understand what an image shows. Google uses alt text to index images in Google Images and to better understand the context of surrounding content. Pages with well-written alt text rank better in image search and can earn additional traffic through visual results. Missing alt text is a missed opportunity to reinforce your page's topic with relevant keywords.

How to write good alt text

• Be descriptive and specific. Describe what the image actually shows. "Golden retriever playing fetch in a park" is far better than "dog" or "image".
• Keep it concise. Aim for under 125 characters. Screen readers may cut off longer alt text, and overly long descriptions feel unnatural.
• Include relevant keywords naturally. If the image relates to your page topic, work in a keyword. But avoid stuffing keywords where they do not fit.
• Skip "image of" or "photo of". Screen readers already announce the element as an image, so these phrases are redundant.
• Use empty alt for decorative images. If an image is purely decorative (like a divider or background pattern), use alt="" so screen readers skip it.

Alt text and accessibility

Alt text is not just an SEO tool. It is a fundamental accessibility requirement under the Web Content Accessibility Guidelines (WCAG). Screen readers read alt text aloud to visually impaired users, giving them context about images they cannot see. Without alt text, screen readers either skip the image entirely or read the file name, which is usually meaningless. Writing clear alt text ensures your website is usable by everyone, regardless of how they browse. In many countries, accessibility compliance is also a legal requirement.

For a complete on-page review that includes alt text alongside title tags, meta descriptions, and heading structure, run the free site audit.