Free Image Alt Text Checker

What this alt text checker checks

This free alt text checker scans every image on the page you enter and reports which ones are missing a meaningful alt attribute. It flags images where the alt attribute is absent entirely or contains only whitespace. It does not flag images with an empty alt (alt=""), because an empty alt is the correct, valid way to mark a purely decorative image so screen readers skip it.

Results are itemised and grouped by issue type, so you get an actual list to work through rather than just a count: images with missing alt, a filename used as the alt, alt text over the recommended length, and duplicate alt text shared across images. Each row shows the image source and its current alt, which is what makes this practical for a bulk alt text audit.

It works on any platform, so you can use it as an alt text checker for WordPress, an alt text checker for Webflow, Shopify, Squarespace, and any other site, because it reads the live rendered HTML rather than plugging into your CMS.

Why alt text matters

Alt text is the text a screen reader announces in place of an image, so it is essential accessibility: without it, blind and low-vision visitors get nothing where your image should be. It is also a legal expectation under accessibility standards such as WCAG.

For SEO, alt text is how search engines understand what an image shows, which drives Google Images traffic and gives context to the surrounding content. Missing alt text is a common, easily fixed gap that costs you image search visibility for free.

How to write good alt text

Describe the image the way you would to someone who cannot see it, in the context of the page:

• Be specific and concise: aim for roughly 125 characters or fewer, which is around where many screen readers pause. Describe what matters, not every detail.
• Do not start with "image of" or "picture of": screen readers already announce that it is an image.
• Skip keyword stuffing: write for a human. One natural mention of a relevant term is fine; a list of keywords reads as spam and helps no one.
• Mark decorative images with alt="": if an image is purely decorative (a divider, a background flourish), an empty alt tells assistive tech to skip it.

Fixing alt text on WordPress and Webflow

On WordPress, set alt text in the Media Library or in the block settings for each image; the Alternative Text field sits in the block sidebar when an image is selected. Updating it in the Media Library updates it everywhere that image is used.

On Webflow, static images take an alt attribute in the Settings panel of the selected image element, and CMS collection images need the alt field bound to a text field in the collection (a very common miss, since an unbound field ships every image with no alt). A full AuditZap audit returns AI fix instructions naming the exact WordPress field or Webflow binding to change for each flagged image.

Auditing alt text across your whole site

This tool checks one page at a time. For a bulk alt text audit across your site, run a full AuditZap audit: it crawls up to 10 pages on the free plan (50 on Pro), lists every unique image missing alt text, and packages the findings into a shareable PDF report you can hand to a client or a developer.