How do I install the Duplicate JS skill?

Run npx skillmds@latest add thedaviddias/duplicate-js in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Duplicate JS safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Duplicate JS?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Duplicate JS free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Duplicate JS?

thedaviddias (@thedaviddias) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Duplicate JS by thedaviddias — Agent Skill

Name: Duplicate JS
Author: thedaviddias

Duplicate JS

Use when auditing slow page loads, heavy assets, or rendering delays related to Remove duplicate JavaScript libraries. Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes.

thedaviddias bb79049 2 files · 5.2 KB Updated Sep 17, 2026

File contents

Remove duplicate JavaScript libraries

Duplicate libraries increase bundle size and memory usage, and can lead to unexpected behavior or conflicts between different versions of the same code.

Quick Reference

Detect and remove multiple versions of the same library
Use a single version across the entire application
Audit third-party scripts for bundled dependencies

Check

Identify duplicate JavaScript libraries or multiple versions of the same library being loaded using Lighthouse or bundle analysis tools.

Fix

Consolidate dependencies to use a single version and ensure third-party scripts don't bring in redundant libraries.

Explain

Explain the risks of loading duplicate JavaScript libraries and how it impacts performance and stability.

Code Review

Review the routes, assets, and loading behavior that affect Remove duplicate JavaScript libraries. 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.

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

Rule page: https://frontendchecklist.io/en/rules/performance/duplicate-js

Frequently asked questions