Image Alt-Text Auditor
Paste any HTML and get a verdict on every image: missing alt attributes, empty alts, alts that are just filenames, keyword-stuffed alts, and alts too long for screen readers, plus a count of images missing width and height attributes.
Parsed locally with DOMParser, no scripts run, nothing is uploaded.
What the auditor checks
The tool parses your HTML into an inert document with the browser's DOMParser, so nothing in the pasted code ever executes, then inspects every img element. Each image gets one verdict: missing alt attribute (the worst case, screen readers fall back to the filename), empty alt (valid, but only for decorative images), alt over 125 characters (screen readers tend to truncate around there), alt that looks like a filename such as IMG_4032.jpg, alt with a word repeated three or more times (stuffing), or good.
Why width and height matter too
Alongside the alt audit, the tool counts images missing explicit width and height attributes. Without them the browser cannot reserve space before the image loads, so the page jumps as images arrive. That jumping is Cumulative Layout Shift, a Core Web Vitals metric, and adding the two attributes is the cheapest CLS fix available.
How to fix what it finds
- Missing alt: add one. Describe what the image communicates in this context, not its pixels.
- Empty alt on a meaningful image: write a real description. Keep alt="" only for decoration.
- Filename alts: these are CMS defaults nobody edited. Replace with a sentence a person would say.
- Stuffed alts: cut to one natural mention of the topic. Stuffing helps nothing and reads as spam.
Frequently asked questions
Is an empty alt ever correct?
Yes. An empty alt (alt="") is the correct markup for purely decorative images, it tells screen readers to skip the image entirely. The key is that it must be a decision, not an accident. A product photo or chart with an empty alt is a missed signal, a divider flourish with one is exactly right.
Do alt texts affect rankings?
For image search, clearly yes, alt text is one of the strongest signals Google has about what an image shows. For regular page rankings the effect is marginal, alt text is one small relevance signal among many. For accessibility it always matters, screen-reader users depend on it regardless of SEO.
How long should alt text be?
Long enough to describe the image's function in context, and usually under 125 characters. Many screen readers truncate or pause around that length. Describe what the image communicates on this page, not every visual detail.
Should alt text include keywords?
Only when the image is genuinely about the keyword. If the photo shows a standing desk and the page targets standing desks, naming it is natural and helpful. Repeating the keyword or cramming variants into the alt is stuffing, and it reads terribly to the people the attribute exists for.