Scan any webpage to find images with missing, empty, or suspicious alt text. Improve accessibility and SEO with actionable recommendations for every image.
Alt text (alternative text) provides a textual description of images for users who cannot see them. Screen readers read alt text aloud, enabling blind and visually impaired users to understand image content. Without alt text, images are invisible to assistive technology users, creating barriers to understanding your content. WCAG 2.1 Success Criterion 1.1.1 requires that all non-decorative images have text alternatives.
Good alt text is concise (typically under 125 characters), descriptive of the image content and purpose, and contextually relevant to the surrounding content. It should convey what the image communicates, not just what it looks like. Avoid starting with 'image of' or 'picture of' since screen readers already announce it as an image. For complex images like charts or infographics, provide a brief summary in alt text and a longer description elsewhere on the page.
Images that are purely decorative — such as borders, spacers, background patterns, or visual flourishes that add no informational value — should have an empty alt attribute (alt=""). This tells screen readers to skip the image entirely, preventing unnecessary noise. Note that an empty alt attribute (alt="") is different from a missing alt attribute: the former is intentional, while the latter is an accessibility violation.
Missing alt text negatively impacts SEO in multiple ways. Search engines use alt text to understand image content and context, which influences image search rankings and overall page relevance. Google explicitly recommends providing descriptive alt text for images. Pages with missing alt attributes may also receive lower accessibility scores in Core Web Vitals assessments, which can indirectly affect search rankings. Additionally, accessible sites tend to have better engagement metrics, which are positive ranking signals.
An alt text checker scans a single page for image accessibility issues — missing alt attributes, empty alt text, and suspicious placeholder values. A full UX audit, like those provided by VertaaUX, goes much further: it checks WCAG 2.2 compliance across dozens of criteria, evaluates color contrast, keyboard navigation, form accessibility, semantic structure, and more. It also audits usability, performance, and conversion factors across your entire site. Use an alt text checker for quick image checks, and a full audit for comprehensive accessibility coverage.
Checking alt text is just one part of accessibility. To audit every element across your whole site for WCAG 2.2 compliance — including contrast, keyboard navigation, forms, and more — run a free UX audit with VertaaUX.
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