performance-vitals
Optimize Core Web Vitals
Performance regressions are hard to catch when teams review LCP, INP, and CLS late. This skill gives Claude, Codex, and Claude Code focused guidance for measuring, diagnosing, and fixing Core Web Vitals issues.
Install with my Agent
Copy this request to your Agent. It includes the canonical Skill page and manifest.
Review the Skillstore skill "performance-vitals" from https://skillstore.io/skills/doyajin174-performance-vitals.md and its manifest at https://skillstore.io/api/skills/doyajin174-performance-vitals/manifest. Verify the artifact. You may proceed after verification, subject to the environment's own policy.Your Agent should still show its plan and request any confirmation required by the security policy.
Agent-readable resources
Use these links when an AI agent, crawler, or script needs clean context instead of reading the full page.
Test it
Using "performance-vitals". A home page has a slow hero image and LCP above four seconds.
Expected outcome:
The response identifies the hero image as the likely LCP element and recommends priority loading, modern formats, dimensions, and server checks.
Using "performance-vitals". A search box delays typed input when the results list updates.
Expected outcome:
The response separates urgent input updates from deferred results work and recommends splitting long tasks or using a worker for heavy processing.
Using "performance-vitals". A marketing page shifts when fonts and banners load.
Expected outcome:
The response recommends reserving space, defining media dimensions, using font display controls, and avoiding layout-changing animations.
Security Audit
SafeStatic alerts are caused by Markdown code fences, placeholder URLs, a local Web Worker sample, and a Lighthouse example command. I found no evidence of prompt injection, credential access, arbitrary command construction, or unauthorized data exfiltration in SKILL.md.
Risk Factors
β‘ Contains scripts (1)
βοΈ External commands (36)
π Network access (7)
Share & cite this report
Share the versioned assessment report, neutral badge, embed card, and citations. Skillstore reports evidence without deciding whether this Skill is safe.
Copy report link
https://skillstore.io/skills/doyajin174-performance-vitals/audits/8?utm_source=security_passport&utm_medium=share&utm_campaign=versioned_reportMarkdown badge
[](https://skillstore.io/skills/doyajin174-performance-vitals?utm_source=security_passport_badge)HTML badge
<a href="https://skillstore.io/skills/doyajin174-performance-vitals?utm_source=security_passport_badge"><img src="https://skillstore.io/badges/skills/doyajin174-performance-vitals/security.svg" alt="Skillstore security assessment" loading="lazy"></a>Embed card
<iframe src="https://skillstore.io/embed/skills/doyajin174-performance-vitals.html" title="Skillstore Security Assessment" sandbox="allow-popups allow-popups-to-escape-sandbox" loading="lazy" referrerpolicy="no-referrer" width="420" height="180"></iframe>Academic citations (APA Β· BibTeX Β· CFF)
APA citation
Doyajin174. (2026). performance-vitals security audit report (audit version 8) [Author version 1.0]. Skillstore. https://skillstore.io/skills/doyajin174-performance-vitals/audits/8BibTeX citation
@techreport{doyajin174-doyajin174-performance-vitals-2026,
author = {Doyajin174},
title = {performance-vitals security audit report (audit version 8)},
institution = {Skillstore},
year = {2026},
number = {8},
url = {https://skillstore.io/skills/doyajin174-performance-vitals/audits/8},
note = {Author version 1.0}
}CITATION.cff
cff-version: 1.2.0
message: "If you use this Skill, cite its author and this versioned security audit report."
title: "performance-vitals security audit report (audit version 8)"
version: "1.0"
type: report
authors:
- name: "Doyajin174"
date-released: "2026-07-05"
url: "https://skillstore.io/skills/doyajin174-performance-vitals/audits/8"
identifiers:
- type: other
value: "skillstore:doyajin174-performance-vitals:audit:8"
description: "Skillstore immutable audit report identifier"
Skillstore Score
Why this score Evidence Confidence: HighWhat You Can Build
Review a Frontend Feature
Check a new page or component for likely LCP, INP, and CLS regressions before release.
Create a Performance Checklist
Build a shared review checklist for image loading, interaction latency, layout stability, and monitoring.
Plan Lighthouse CI Gates
Define route coverage and performance budgets that can catch regressions during pull request checks.
Try These Prompts
Review my page for LCP, INP, and CLS risks. Explain the likely causes and suggest the first fixes.
Review this React feature for input latency, layout shift, and render blocking. Suggest changes I can apply before release.
Create a Lighthouse CI performance budget plan for these routes. Explain which thresholds should fail a pull request.
Compare these Lighthouse and field data results. Identify the likely regression source and create a prioritized remediation plan.
Best Practices
- Measure pages before and after each optimization.
- Treat LCP, INP, and CLS as separate failure modes.
- Use CI budgets and field monitoring to catch regressions.
Avoid
- Optimizing only lab scores while ignoring field data.
- Adding third-party scripts without measuring input delay.
- Loading images or dynamic content without reserved space.
Frequently Asked Questions
Does this skill run audits automatically?
Which metrics does it cover?
Can it help with Next.js projects?
Does it require network access?
Can it replace field monitoring?
Is it only for developers?
Developer Details
Author
Doyajin174License
MIT
Author version
v1.0
Skillstore revision
r1
Version notice
The author-declared version is not valid SemVer.
Ref
c579efd02184f1128d6741d16e6c8d951d7d4208
Maintenance freshness
7/18/2026
Usage
5 downloads Β· 245 views
File structure
π SKILL.md