Why it matters
An image button without alt text is announced by its file name or not at all, so screen-reader users cannot tell what it submits.
How to fix it
Add alt text that describes the action (not the picture).
Example
<input type="image" src="/search.svg" alt="Search">References
More accessibility rules
void a11y reports 48 rules in this category. WCAG 2.2 AA through axe-core, plus checks axe can't do alone: visible keyboard focus, 24/44px target size on mobile, 320px reflow and disabled zoom.
link-nameLink has no accessible namelabelForm field has no labelselect-nameSelect element has no accessible nameinput-button-nameInput button has no accessible namehtml-has-lang<html> has no lang attributehtml-lang-valid<html lang> is not a valid language tagdocument-titlePage has no <title>landmark-one-mainPage has no <main> landmark