Image Alt Text Checker

What This Checks

Enter a URL and the checker returns every img element with its alt attribute, its file name, and its dimensions. Missing attributes are separated from empty ones, because those two states mean opposite things and are constantly confused.

A missing alt attribute is a defect: assistive technology has nothing to announce and will often read the file name instead, which produces things like "I M G underscore 4 0 2 1 dot j p g". An empty alt="" is a deliberate instruction meaning the image carries no information and should be skipped. Decorative dividers, background textures, and spacer images should all have empty alt, and adding descriptions to them makes a page worse to listen to, not better.

Reading the Output

FILE                    ALT TEXT                     STATUS
hero-team.jpg           Four people at a standing     ok
                        desk reviewing a chart
divider-wave.svg        (empty)                       ok, decorative
IMG_4021.jpg            (missing)                     needs alt
pricing-table.png       pricing table                 too vague
logo-acme.svg           Acme                          ok
banner-cta.jpg          project management software   keyword stuffed
                        project management tool
                        best project management

3 of 6 need attention

The last row is the failure worth naming. Alt text stuffed with search terms is read aloud, in full, to a person using a screen reader. It is a poor experience delivered to the users the attribute exists to serve, in exchange for a benefit that does not really exist.

"pricing table" is the more common problem: technically present, functionally useless. The test for good alt text is whether someone who cannot see the image gets the same information from your sentence that a sighted reader gets from the picture. If the image shows three plans at three prices, say that.

Writing Alt Text That Works

Describe function, not appearance. An image used as a link should describe where the link goes, not what the picture looks like. A chart should state its finding rather than listing its axes. A photograph illustrating a point should say what is happening in it.

Skip "image of" and "picture of" at the start. Assistive technology already announces that it is an image, so the prefix is heard twice. Keep it to a sentence where possible; anything that needs a paragraph is probably carrying information that belongs in the page text where everyone can reach it.

There is a search benefit and it is real but modest: alt text is how image search understands a picture, and it is what displays when an image fails to load. Neither is a reason to write for machines instead of people.

Questions