Image alt tags checker

What the image alt tags checker does

This tool scans a webpage, counts its images, and reports how many of them are missing alt attributes. It flags each image without alt text so you can review and fix the gaps.

The alt attribute provides a textual alternative for an image. When an image cannot be displayed, the alt text is shown instead. For screen readers, it is the primary way to convey what an image contains. For search engines, it offers context about the image's subject and its relationship to the surrounding content.

Why alt text matters

Accessibility is the strongest reason to write alt text. Users who rely on assistive technology need a description of meaningful images to understand a page. Decorative images are a separate case: they should typically have an empty alt attribute, alt="", so screen readers can skip them without announcing noise.

From an SEO perspective, alt text helps image search understand what an image depicts. It is not a place for keyword stuffing; repeated keyword strings read poorly to assistive technology users and add little value. A concise, accurate description is more useful than a list of search terms.

How to interpret the results

The summary shows the total number of images and how many lack alt text. Each flagged image is labeled as missing an alt tag. A missing alt attribute is different from an empty one: missing means the attribute is absent entirely, while empty means it is present but intentionally blank. Both can be acceptable depending on the image's role, but missing attributes on content images are a clear gap.

When reviewing flagged images, ask what each image contributes. A product photo, chart, or infographic usually needs descriptive alt text. A spacer, background flourish, or purely decorative icon should have an empty alt. Icons that act as buttons need text that describes the action, not the picture.

Writing useful alt text

• Be specific but brief. Describe what matters in the image, usually in a sentence or less.
• Avoid redundant phrasing. Screen readers already announce that the element is an image, so starting with "image of" is usually unnecessary.
• Match the context. The same photo may need different alt text depending on the page it supports.
• Do not stuff keywords. Write for a person who cannot see the image.
• Use empty alt for decoration. This prevents assistive technology from announcing non-informative images.

Practical workflow

Run the checker on image-heavy templates such as product listings and blog posts. Fix content images first, since they carry the most meaning. Then review decorative images and confirm they use empty alt attributes rather than missing ones. Re-run the check after CMS or theme updates, because template changes can drop alt attributes across many pages at once.

Limitations

The checker examines the HTML response for alt attributes. It does not evaluate whether the alt text is accurate or helpful, and it does not detect images inserted dynamically by client-side scripts if they are absent from the initial HTML.