Image SEO analyser

How to use it

1. 1Enter the address you want to checkType or paste it into the field marked "Address to check", including the https:// at the front. Use a page with real images on it — a gallery, a product page, an article with photographs.
2. 2Press Check and wait a few secondsThe request runs from our server rather than from your browser, so your cache, your extensions and your login session cannot affect the answer. That is the point of it: you are seeing what an anonymous visitor sees.
3. 3Fix missing alt text firstAn image with no alt attribute is invisible to a screen reader and says nothing to a search engine. An image that is purely decorative should carry an EMPTY alt rather than no alt — the tool distinguishes the two, because they mean opposite things.
4. 4Look at the oversized filesEvery image is measured, and anything served much larger than it is displayed is reported with both numbers. This is usually the single biggest thing slowing a page down, and it is usually a one-line fix.
5. 5Check the modern-format and lazy-loading notesWebP or AVIF instead of JPEG, and lazy loading on images below the fold, are both cheap wins. Neither is a rule — the tool reports what is there rather than insisting.
6. 6Share or keep the result within 24 hoursThe result has its own link you can send to whoever needs to act on it. It is deleted 24 hours after the check ran, so save anything you need to keep — and re-run the check after a change rather than trusting an old link.

About this tool

This tool reads every image on a page and reports how it is described, whether the browser can reserve space for it before it arrives, how it loads, what format it is and what it weighs.

It is careful about one thing that most tools of this kind get wrong: an empty alt attribute is correct. It is how you tell a screen reader that an image is decorative and should be skipped. A missing alt attribute is the defect. Treating the two the same sends people to write descriptions for spacer graphics, which makes a page worse rather than better.

Understanding the result

Images are counted as described, decorative or missing an alt. Only the last is a problem.

A missing alt on an image that is the entire content of a link is worse than a missing alt elsewhere: the alt text is the link's name, so without it a visitor hears the URL read aloud.

Width and height attributes let the browser reserve the right space before the image arrives. Both are needed — one alone still leaves the box unknown — and their absence is what people describe as "the page moved while I was reading it".

Weight and format come from opening the image, so those findings cover only the images we opened. Alt text and dimension findings cover all of them, and the result says which is which.

Example

https://example.com/gallery

24 images · 3 with no alt attribute (1 inside a link)
7 marked decorative with alt="" — correct
18 of 24 do not declare width and height
2 images over 250 KB · 0 modern format

Limitations

• Read from the raw HTML. Images inserted by JavaScript after load are not seen.
• CSS background images are not covered. They are presentational and carry no alt text by design.
• We report file weight from the response, not pixel dimensions, so we cannot tell you a 4000px image is being displayed at 400px — the commonest real cause of a heavy page.
• The weight threshold is advisory and is carried with the result. A hero photograph legitimately exceeds it.
• Whether alt text is *good* is a judgement about writing. We can spot a filename masquerading as a description; we cannot tell you whether a description is accurate.

Questions