Content readable at 400% zoom without scrolling
What this criterion checks
This criterion maps to 1.4.10. Reflow (AA). A detailed plain-language description is maintained in the WebLens criteria catalogue; the WCAG sub-test breakdown below describes exactly what the agent checks and what it does not.
How it's assessed
WebLens walks each user journey, captures a screenshot at every step, and an agent reasons over that evidence. See the how WebLens works for the full pipeline and the deterministic checks layered in for accessibility.
Sub-test coverage
1.4.10. Reflow (AA) is broken into 3 sub-tests. Coverage is honest about where the agent is reliable, where it only partially checks the requirement, and where a human reviewer is still needed.
2 full1 partial
- Content reflows at 400% zoom without requiring horizontal scrollingFull
Our tool zooms the page to 400% (equivalent to a 320-pixel-wide viewport) and checks whether horizontal scrolling is needed. It uses both a direct measurement of whether content extends beyond the viewport and a visual inspection for layout issues. If either method detects horizontal scrolling, it is flagged.
- Elements do not overlap at 400% zoomFull
Our tool specifically checks for overlapping elements at 400% zoom — such as navigation covering main content or headers obscuring text. It reports the specific areas where overlap occurs.
- No content or functionality is lost at 400% zoomPartial
At 400% zoom, our visual inspection checks for content that is cut off or hidden. However, thoroughly verifying that all content and functionality from the normal view is still accessible requires navigating the full page at high zoom — especially content in menus, tabs, or expandable sections that may behave differently. Content that legitimately needs two-dimensional layout (data tables, maps, images) should be confirmed as valid exceptions by a person.
How reliable it is
This criterion performs well against expert review. Treat its findings as strong leads and confirm before remediating. See Accuracy & confidence for how the confidence tags are set.