7.3The Three-Tier Strategy

+------------------------------------------------------+
|  Tier 1: Full Regression (every PR)                  |
|  Chrome (latest) + Firefox (latest) + Safari (latest)|
|  These 3 cover ~92% of desktop users                 |
+------------------------------------------------------+
|  Tier 2: Critical Path (weekly / release)            |
|  Chrome Android + Safari iOS + Edge                  |
|  Samsung Internet + Firefox Android                  |
+------------------------------------------------------+
|  Tier 3: Spot Check (monthly / quarterly)            |
|  Older Safari (2 versions back)                      |
|  Chrome on low-end Android                           |
|  UCBrowser / Opera Mini (if emerging market users)   |
+------------------------------------------------------+

Tier 1: Full Regression on Every PR

Run your entire test suite against the latest versions of Chrome, Firefox, and Safari. These three browsers represent the three rendering engines and cover the vast majority of users.

// playwright.config.ts -- Tier 1 configuration
import { defineConfig, devices } from '@playwright/test';

export default defineConfig({
    projects: [
        {
            name: 'chrome',
            use: { ...devices['Desktop Chrome'] },
        },
        {
            name: 'firefox',
            use: { ...devices['Desktop Firefox'] },
        },
        {
            name: 'safari',
            use: { ...devices['Desktop Safari'] },
        },
    ],
});

Tier 2: Critical Paths on Release

Test the most important user journeys (login, search, checkout, payment) on mobile browsers and less common desktop browsers:

// playwright.config.tier2.ts
export default defineConfig({
    projects: [
        {
            name: 'chrome-android',
            use: { ...devices['Pixel 7'] },
        },
        {
            name: 'safari-ios',
            use: { ...devices['iPhone 15'] },
        },
        {
            name: 'edge',
            use: { channel: 'msedge' },
        },
    ],
    // Only run critical path tests
    testMatch: '**/critical-path/**',
});

Tier 3: Spot Checks

Manual or semi-automated checks on older browsers and niche platforms. These do not need to run in CI:

# Quarterly checklist for Tier 3 browsers
# Run manually on BrowserStack/Sauce Labs:
# - Safari 2 versions back: login + main page + checkout
# - Chrome on Android 12 (low-end): page load under 5s
# - Samsung Internet: form submission + file upload
# - Opera Mini: basic content rendering (no JS-heavy features)