An image tag with no alt attribute at all, not an image with alt="" left intentionally empty. This checker flags only the true absence of the attribute as missing, since an empty alt is a valid, deliberate way to mark a decorative image that should be skipped by screen readers.
Is it bad for an image to have an empty alt attribute?
Not if the image is purely decorative and adds no information a visitor needs, such as a divider graphic or a background pattern. For any image that conveys real content or function, like a product photo or a button icon, it should have a real description instead of an empty attribute.
Why does this checker flag alt text that looks like a filename?
Because text like IMG_4821.jpg or product-shot_v2_final technically fills the alt attribute but describes nothing about the image's actual content. It usually happens when a content management system autofills alt text from the uploaded file name and nobody replaces it with a real description afterward.
How long should alt text be?
There is no strict limit, but a common guideline keeps it under roughly 125 characters, since some screen readers truncate or handle longer text less gracefully. Aim for a specific, concise description rather than a long list of keywords.
Does this tool crawl my live website?
No. Paste the HTML source directly and everything runs in your browser; nothing is uploaded or sent to a server. To get a page's HTML, view its page source or use your browser's inspector and copy the markup here.
What is a good alt text coverage percentage to aim for?
100% is the realistic target for any image that is not purely decorative, since every meaningful image should describe itself to both screen readers and search engines. Genuinely decorative images marked with an empty alt attribute are counted separately and do not count against your coverage in a way that should worry you.