Performance
The performance skill identifies and resolves web performance bottlenecks through Lighthouse-based audits, prioritizing optimizations by their impact on Core Web Vitals and providing specific code examples. It serves developers and site owners who need to improve page speed, reduce load times, and enhance user experience across loading speed, runtime efficiency, and resource optimization. The skill solves the problem of slow-loading websites by establishing performance budgets, optimizing the critical rendering path, and guiding implementation of techniques like code splitting, asset preloading, and compression.
- skills.sh installs
- 43.7K
- GitHub stars
- 3.1K
- last updated
- Aug 21, 2026
Install
$ npx -y skills add addyosmani/web-quality-skills --skill performance --agent claude-codeInstalls into .claude/skills of the current project.
Files
Performance optimization
Evidence-led performance optimization using real-user signals for prioritization and browser traces for diagnosis. Focuses on loading speed, runtime responsiveness, and resource delivery.
How it works
- If a page can run, read the measurement workflow and establish a field-plus-lab baseline before editing.
- Prioritize poor real-user Core Web Vitals. Use a DevTools performance trace and its focused insights to find the cause.
- Inspect and change only the code or assets connected to measured bottlenecks.
- Re-run equivalent lab measurements and report before/after values, conditions, and uncertainty. Field verification remains pending until enough new user data arrives.
When no runnable page exists, perform static inspection but call findings hypotheses, not measured regressions. Include the command or browser workflow that can verify each high-impact hypothesis.
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- Repository
- github.com/addyosmani/web-quality-skills
- Categories
- Code Review & Quality, Debugging
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