AddThisFeature

Responsive QA Matrix

Decide which screen sizes, zoom levels, and text settings every flow has to survive.

moderate Testing & QA

What it adds

A written matrix of viewports, orientations, zoom levels, and text-size settings that each major flow is tested against.

What your agent is told to do

5
  1. 1

    List the app's major flows, then write down for each the exact widths, orientations, zoom levels, and text-size settings it must pass, so testing stops depending on whichever window size the reviewer happened to have open.

  2. 2

    Include the widths that break layouts rather than only the comfortable ones: the tablet in portrait, the narrow desktop window beside a chat panel, the phone in landscape, and the width just below each breakpoint.

  3. 3

    Include a large-text pass at increased browser font size and at 200 per cent zoom, and treat clipped, overlapped, or unreachable content at those settings as a failure rather than a cosmetic issue.

  4. 4

    Pair each viewport with deliberately hostile content — the longest real name, a translated string that runs half again as long, an empty list, a table with far more rows than expected — because most responsive failures need both a narrow screen and awkward content.

  5. 5

    Record the combinations the app does not support and what happens there, so an unsupported case is a stated decision rather than an untested gap. Browser versions and engines belong to the Browser Support Matrix; this brief owns geometry and text scaling only.

Edge cases it handles

7
  • The awkward middle widths are where layouts actually break — a tablet in portrait, or a desktop window dragged to half the screen — and a matrix that tests only a phone and a full-width desktop will pass while both of those are broken.
  • Increased browser text size and page zoom reflow differently from a narrow viewport, so a layout that survives a phone width can still clip or overlap at 200 per cent zoom on a desktop.
  • A viewport tested with short placeholder content proves nothing; the same width with a long untruncated name, a translated label, or an unexpectedly full table is where the overflow appears.
  • Combinations that are explicitly not supported must be written down along with the intended behaviour there, or every reviewer relitigates the same question and users get an undefined experience.
  • Mobile browser chrome and the on-screen keyboard change the usable height mid-session, so a fixed viewport height in the matrix will not represent what the user actually has.
  • Orientation changes mid-flow can lose scroll position, selection, or an open dialog, and this only shows up if the matrix requires rotating during a flow rather than starting in each orientation.
  • Content that scrolls horizontally inside its own container is acceptable; the page body scrolling horizontally is not, and the matrix must distinguish the two.

Definition of done

8
  • Every major flow has a written list of the viewports, orientations, zoom levels, and text sizes it must pass.
  • The matrix includes tablet portrait, a narrow desktop window, and the width immediately below each breakpoint.
  • Each flow is verified at increased browser text size and at 200 per cent zoom with no clipped or unreachable content.
  • Each viewport is tested with long, translated, empty, and oversized content rather than placeholder text.
  • Unsupported combinations are documented along with the behaviour users get there.
  • No page scrolls the body horizontally at any listed viewport.
  • The feature matches the existing design system.
  • No existing functionality is broken.

Related features

How it works

  1. 1

    Copy the link

    Grab the Markdown instruction URL for this feature.

  2. 2

    Give it to your AI

    Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.

  3. 3

    It inspects, then implements

    Your agent reads your existing app first, then adds the feature to fit it.

Works with your stack

These instructions are written to adapt. They tell the agent to detect your framework, match your existing design system, and reuse what you already have — rather than assuming a particular stack.

Need it tighter than that? Customize the feature and tell it exactly what you're running.