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name: js-libraries description: "Use when auditing slow page loads, heavy assets, or rendering delays related to Use secure and up-to-date JS libraries. Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes." metadata: category: performance priority: medium difficulty: intermediate estimatedTime: "10" source: frontendchecklist.io url: https://frontendchecklist.io/rules/performance/js-libraries

Use secure and up-to-date JS libraries

Outdated or vulnerable libraries pose security risks and often include unnecessary bloat that degrades performance.

Quick Reference

• Regularly audit dependencies for known security vulnerabilities
• Replace heavy libraries with lightweight alternatives (e.g., date-fns vs moment)
• Ensure libraries are properly versioned and served via reliable CDNs or self-hosted

Check

Check the project's JavaScript dependencies for known vulnerabilities and outdated versions.

Fix

Update vulnerable libraries to secure versions and replace bloated dependencies with modern, lightweight alternatives.

Explain

Explain the risks of using outdated JavaScript libraries and the benefits of using lightweight alternatives.

Code Review

Review the routes, assets, and loading behavior that affect Use secure and up-to-date JS 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.

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

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