Accessibility quick check
Thirteen things a screen reader needs, checked in seconds — and an honest note on what this cannot see.
What is checked
The things that can be read reliably from HTML alone: whether the page declares its language, whether images carry alt text, whether headings descend without skipping a level, whether form fields have anything a label could attach to, whether links say where they go, whether pinch zoom has been disabled, and whether the page marks its main regions.
Each one is explained in terms of what actually happens to somebody using the site. "No lang attribute" means a screen reader may read your English with Khmer phonetics, or the reverse — which is the reason to fix it, not the rule number.
What this cannot tell you
Automated tools find roughly a third of real accessibility problems. It is a useful third and the cheapest third, but it is a third. Colour contrast needs the rendered page and its CSS. Keyboard traps need somebody to press Tab. Whether your alt text is any good — as opposed to merely present — needs a person who can see the image and read the sentence.
A page that passes all thirteen of these is not an accessible page. It is a page with no obvious automated failures, which is where the work starts rather than where it finishes.
Why it is worth doing anyway
Most of what fails here fails for everybody, not only for people using assistive technology. Headings that skip levels confuse search engines. Links that say "click here" tell an assistant nothing it can quote. A viewport that blocks zoom annoys anyone over forty on a phone.
The overlap between accessibility and being findable is much larger than it looks. Nearly every fix on this list improves both, which makes it an unusually easy argument to win internally.