Frontend & Design

Responsive Testing

Test layouts across screen sizes and devices to ensure your UI adapts gracefully from mobile to desktop viewports.

Claude Code Cursor Copilot Windsurf

Overview

Responsive testing ensures your application looks and functions correctly across different screen sizes, from mobile phones to ultra-wide desktop monitors. Using tools like Playwright or Chrome DevTools, AI agents can render your pages at various viewport sizes and verify that layouts, navigation, and interactive elements adapt properly.

AI agents can automate what was traditionally a manual, tedious process. Instead of manually resizing your browser window and eyeballing layouts, the agent can programmatically render your page at mobile (375px), tablet (768px), and desktop (1280px) viewports, take screenshots, and verify that no elements overflow, overlap, or break at each breakpoint.

When responsive issues are found, the agent can analyze the CSS, identify which media queries or flex/grid configurations need adjustment, and implement the fix. This is particularly valuable for catching edge cases that developers often miss during manual testing.

Who Is This For?

Frontend developers verifying layouts across mobile, tablet, and desktop breakpoints
Teams automating responsive regression testing in CI pipelines
Designers validating that implementations match responsive design specifications
Developers fixing overflow and layout issues at specific viewport sizes

Installation

Setup for Claude Code

npm install --save-dev @playwright/test
npx playwright install
Claude Code runs viewport tests via Playwright

Configuration

// responsive.spec.ts
import { test } from "@playwright/test";

const viewports = [
  { name: "mobile", width: 375, height: 812 },
  { name: "tablet", width: 768, height: 1024 },
  { name: "desktop", width: 1280, height: 720 },
];

for (const vp of viewports) {
  test(`layout at ${vp.name}`, async ({ page }) => {
    await page.setViewportSize({ width: vp.width, height: vp.height });
    await page.goto("/");
    // assertions here
  });
}