SkillsAdd

thedaviddias/front-end-checklist

js-file-size

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

First seen Jun 8, 2026

Installation

$ npx skills add thedaviddias/front-end-checklist --skill js-file-size
View on skills.sh ↗ GitHub repository ↗

Similar popular skills

Related neighbors and high-traction skills in the same topics — useful to compare before installing.

gws-workflow-file-announce Similar name
googleworkspace/cli

Google Workflow: Announce a Drive file in a Chat space.

27.8K installs
recipe-find-large-files Similar name
googleworkspace/cli

Identify large Google Drive files consuming storage quota.

27.2K installs
multi-stage-dockerfile Similar name
github/awesome-copilot

Create optimized multi-stage Dockerfiles for any language or framework

23.4K installs
write-coding-standards-from-file Similar name
github/awesome-copilot

Write a coding standards document for a project using the coding styles from the file(s) and/or…

9.6K installs
update-markdown-file-index Similar name
github/awesome-copilot

Update a markdown file section with an index/table of files from a specified folder.

9K installs
troubleshooting-s3-files Similar name
aws/agent-toolkit-for-aws

Diagnoses and resolves Amazon S3 Files issues including mount failures, permission errors, sync…

4.7K installs

Also in this package

Other skills from thedaviddias/front-end-checklist · top by installs.

npx skills add thedaviddias/front-end-checklist
frontend-checklist-global 96 color-contrast 22 animation-performance 22 https 19 pdf-size 18 word-count 18 image-optimization 18 cumulative-layout-shift 18 mobile-testing 18 quality 17

Browse all from thedaviddias/front-end-checklist

More details

Agent compatibility

Declared targets from SKILL.md / docs. Unmarked agents are not listed — the skill may still install via the CLI.

Claude Code Not declared
Cursor Not declared
Codex Not declared
GitHub Copilot Not declared
Windsurf Not declared
Gemini CLI Not declared
Cline Not declared
OpenCode Not declared

Repository health

Stars 74.1K
License MIT
Default branch main
Open issues 5
Status Active

Skill metadata

Parsed from SKILL.md frontmatter.

More metadata
category
performance
priority
medium
difficulty
intermediate
estimatedTime
10
source
frontendchecklist.io
url
https://frontendchecklist.io/en/rules/performance/js-file-size

Package contents

Files included with this skill beyond the listing page.

  • skill md SKILL.md 1,635 B
  • docs SUMMARY.md 229 B

History

  1. First seen on skills.sh
  2. First recorded snapshot · 6 installs

SKILL.md

Optimize JavaScript bundle size

Excessive JavaScript increases parse and execution time, especially on low-end devices, leading to sluggish user experiences and high data costs.

Quick Reference

  • Keep individual JS bundles under 200KB (compressed)
  • Large bundles delay Time to Interactive (TTI) and First Input Delay (FID)
  • Use code-splitting and tree-shaking to reduce unused code

Check

Review the JavaScript bundle sizes and identify any files exceeding 200KB (Gzip/Brotli).

Fix

Implement code-splitting, tree-shaking, and dependency audits to reduce the size of the JavaScript bundles.

Explain

Explain how large JavaScript files impact the main thread and delay user interactivity (FID/TTI).

Code Review

Review the routes, assets, and loading behavior that affect Optimize JavaScript bundle size. 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/js-file-size