# Browser Required

> Use when auditing slow page loads, heavy assets, or rendering delays related to Perform browser-based performance audits. Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes.

- Skill: `thedaviddias/browser-required` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add thedaviddias/browser-required`
- Raw SKILL.md: https://api.skillmd.com/api/skills/thedaviddias/browser-required/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: thedaviddias (https://skillmd.com/u/thedaviddias)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/thedaviddias/browser-required

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# Perform browser-based performance audits

Static analysis alone cannot simulate the complex rendering, script execution, and layout processes of modern web browsers, which is essential for capturing real-world performance.

## Quick Reference

- Use real browser engines to capture runtime metrics (LCP, CLS, INP)
- Synthetic tests in full browsers reveal execution bottlenecks
- Verify performance across different device and connection simulations

## Check

Ensure that performance audits are conducted in an environment that executes JavaScript and renders the page (e.g., Lighthouse, Puppeteer).

## Fix

Integrate browser-based testing tools like Lighthouse or WebPageTest into the development workflow and CI/CD pipeline.

## Explain

Explain the limitations of static analysis for performance and why a full browser environment is necessary.

## Code Review

Review the routes, assets, and loading behavior that affect Perform browser-based performance audits. Flag exact files, requests, or rendering steps that add unnecessary network, CPU, or layout cost, and describe the measurement method used to confirm the issue.

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For full implementation details, code examples, and framework-specific guidance,
see `references/rule.md`.

Rule page: https://frontendchecklist.io/en/rules/performance/browser-required