- Success Criterion 1.4.10
- Conformance level AA
Floating Chat Widget Blocking Content at Mobile Width
1.4.10 — Reflow
Scenario
Setting
A used-car marketplace's listing filter
What’s wrong
Chat widgets/floating buttons overlapping and blocking content at 320px.
Example
During an audit of a used-car marketplace's listing filter: chat widgets/floating buttons overlapping and blocking content at 320px.
Why it matters
Low-vision users at high zoom and people reading on narrow mobile viewports. On a used-car marketplace's listing filter specifically, they can't perceive the control's boundary or state.
How to test
Set the viewport to 320px and check floating chat widgets/buttons: if they overlap and block page content with no way to dismiss or reposition them, it fails.
How to fix
At 320 CSS px width (400% zoom on a 1280px desktop), content must reflow into one column with only vertical scrolling and nothing missing or unreachable.
Outcome
Fixed, a visitor to a used-car marketplace's listing filter can see the control's boundary and current state.
Who is affected
Low-vision users at high zoom and people reading on narrow mobile viewports.
Learn more
- Understanding Understanding document (opens in a new tab)
Related scenarios
- Content or Controls That Vanish Entirely When the Page Reflows
- Vertical Content That Forces Horizontal Scrolling at 320px
- Fixed-Width Container Forcing Scrolling in Two Directions
- Overlapping Content When the Page Is Zoomed to 400%
- Sticky Bars That Eat Up Most of a 320px Mobile Screen
- Desktop Breakpoint That Never Switches to Mobile Layout