Testing Browser Compatibility

What it does

When your agent uses it

• Ensuring cross-browser
• Device compatibility with BrowserStack
• With phrases like test browser compatibility
• Check cross-browser

Example prompts

• “test browser compatibility”
• “check cross-browser”
• “validate on browsers”
• “/testing-browser-compatibility”

Requirements

• Node.js
• A credential in ACCESS_KEY
• A credential in API_KEY
• Compatibility (from SKILL.md): Designed for Claude Code
• Pre-approved tools (allowed-tools): Read, Write, Edit, Grep, Glob, Bash(npx playwright:*), Bash(npm:*), Bash(curl:*)

Workflow steps

4 steps, taken from the first numbered list in SKILL.md.

1. 1Define the browser matrix from project browserslist config or use defaults
2. 2Scan the codebase for compatibility risks
3. 3Write compatibility-focused tests
4. 4Execute and capture results

What it can do on your machine

Read from SKILL.md and the folder at commit 80f86df. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • Read
  • Write
  • Edit
  • Grep
  • Glob
  • Bash(npx playwright:*)
  • Bash(npm:*)
  • Bash(curl:*)

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • npx

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Links to these hosts (documentation or services it may open):

  • playwright.dev
  • caniuse.com
  • browserstack.com
  • docs.saucelabs.com
  • lambdatest.com
  • api.kobiton.com
  • github.com

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names these keys or tokens, usually read from environment variables:

  • ACCESS_KEY
  • API_KEY

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

• Compatibility

  Designed for Claude Code

  From compatibility in the SKILL.md frontmatter.

Context cost

Testing Browser Compatibility loads about 1.7k tokens when it runs, and up to ~9k if it reads all its reference files. Until then it costs about 90 tokens; SKILL.md has 554 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~90

When it runs · the whole SKILL.md, loaded when a task matches

~1.7k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~9k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from jeremylongshore/tons-of-skills-marketplace at commit 80f86df, republished under its MIT licence (© jeremylongshore). 554 words, ~1,738 tokens.

name

testing-browser-compatibility

description

Test across multiple browsers and devices for cross-browser compatibility. Use when ensuring cross-browser or device compatibility with BrowserStack, Sauce Labs, LambdaTest, or Kobiton. Trigger with phrases like "test browser compatibility", "check cross-browser", "validate on browsers", "test on real devices", "kobiton test".

allowed-tools

Read, Write, Edit, Grep, Glob, Bash(npx playwright:*), Bash(npm:*), Bash(curl:*)

compatibility

Designed for Claude Code

version

2.20.0

author

Jeremy Longshore <jeremy@intentsolutions.io>

license

MIT

tags

testing, cross-browser, mobile-testing, real-device, cloud-testing

import { defineConfig, devices } from '@playwright/test';
export default defineConfig({
  projects: [
    { name: 'chromium', use: { ...devices['Desktop Chrome'] } },
    { name: 'firefox', use: { ...devices['Desktop Firefox'] } },
    { name: 'webkit', use: { ...devices['Desktop Safari'] } },
    { name: 'mobile-chrome', use: { ...devices['Pixel 7'] } },
    { name: 'mobile-safari', use: { ...devices['iPhone 14'] } },
  ],
});

test('nav renders correctly across browsers', async ({ page }) => {
  await page.goto('/');
  const nav = page.locator('nav');
  await expect(nav).toBeVisible();
  const box = await nav.boundingBox();
  expect(box.width).toBeGreaterThan(300);
});

{
  "platformName": "iOS",
  "appium:deviceName": "iPhone 15 Pro",
  "appium:platformVersion": "17",
  "browserName": "Safari",
  "kobiton:options": {
    "sessionName": "Safari Compat Test",
    "deviceGroup": "KOBITON",
    "captureScreenshots": true
  }
}

© jeremylongshore, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 3 other files (references) in skills/.curated/testing-browser-compatibility of jeremylongshore/tons-of-skills-marketplace.

• SKILL.md
• references/ci-cd-integration.md
• references/cloud-providers.md
• references/device-matrix.md

Open the folder on GitHubat commit 80f86df