2056350 - [a11y] Resizing the viewport causes horizontal scrolling

Status: ASSIGNED

(Firefox :: Messaging System, defect, P1)

Description

[Claire Joeckel]

Attachment: Screenshot 2026-07-20 120627.png

Impacted Section/Element

About:welcome flow, HNT

Steps to Reproduce

Resize the window to 1280px wide and use Ctrl + to zoom to 400%.

Expected Behavior

Content reflows neatly and adapts to window size, with no horizontal scrolling required.

Actual Behavior

On the About:welcome flow pages, as zoom level is increased to 400%, content overflows the window and horizontal scrolling is required. On HNT, at 180% zoom or above, content overflows the window and horizontal scrolling is required.

User Impact

Users who zoom content via Ctrl + may experience difficulty using the page.

WCAG 2.2 References

1.4.10 Reflow

Recommendations

Use responsive CSS so that content reflows neatly and does not require horizontal scroll.

Testing Environment

Any

Assistive Technology Used

Any

Further Reference

https://webaim.org/techniques/reflow/

Severity

3-Moderate

Comment 1

[Shane Hughes [:aminomancer]]

It's very difficult to avoid horizontal scrolling when zoomed to such a great level. Even if we avoid wasting space on the left, it may not be possible to avoid scrolling completely. But with bug 2056348, we will try to at least make things look nicer and more responsive.