Checks

Looking at screenshots is slow, for people and for models. So while facetshot has each page open, it also reads the page for problems a reviewer would notice, and lists them as text. Use the list to decide which screenshots are worth opening.

facetshot check /settings /billing          # read only, no screenshots: the fastest way to find problems
facetshot /settings --checks all            # screenshots and every check except a11y

Which checks run

Command	Checks
facetshot <targets> (taking screenshots)	console and network, or the config’s checks if set
facetshot check <targets>	every check except a11y
--checks all	every check except a11y when taking screenshots; every check with check
--checks <names>	only the checks you name, e.g. --checks console,network,a11y

a11y is slower and needs axe-core, which facetshot installs as an optional dependency. Agents choose checks with the checks parameter of the MCP check tool.

What’s checked

Check	Finds	Severity
console	errors the page logged or threw	error
network	requests that failed or answered 4xx or 5xx (blocked requests are left out)	error for 5xx and failures, warning for 4xx
overflow	horizontal scrolling: the page is wider than the screen. Names the element that sticks out furthest	error
clipped	text cut off by its box, a line clamp, or the edge of the screen	warning; info for ellipsis and line clamps, which are usually intended
covered	buttons and links with something else on top, so a tap at their center hits the wrong element	warning
images	images that failed to load	error
blank	a page with no text and no images	error
targets	tap targets smaller than 24×24 on touch devices (links inside running text are exempt, as in WCAG 2.5.8)	warning
a11y	accessibility problems found by axe-core, such as contrast, labels and roles; serious and critical only	error or warning

Reading the results

The summary groups the same finding across devices and variants, so one problem is one line:

Found (3):
  ✗ checkout [phone/light, phone/dark] overflow: The page is 48px wider than the screen, so it scrolls horizontally. — form.payment > div.row
  ! pricing [4 cells] clipped: Text cut off at the side. "Everything in Pro, plus priority support" — li.feature
  ! settings [phone/light] targets: Tap target is 16×16, under 24×24. "×" — header > button.close

✗ is an error and ! a warning. The part after the last dash is where on the page the problem is: a short selector path you can search your code for. Every finding is also in manifest.json under its screenshot, with its check, severity, message, place and text.

On the contact sheet, a screenshot with problems carries a small badge with the count.

Findings are hints

A finding means “look here”, not “this is wrong”. A horizontal carousel overflows on purpose, and a decorative icon button can be small. If a finding is expected on a page, leave that check out with --checks. There is no way to ignore one element yet; web.mask only paints over the screenshot, and the checks still see what’s under it. Findings never change the exit code.