frontend-optimizer

CLI to optimize front-end assets — WebP images, self-hosted fonts, LCP, dimensions, and deferred JS/CSS.

Author: Hamza Haseeb

Install

npm install -g frontend-optimizer

Or run without installing:

npx frontend-optimizer optimize ./your-project

Quick start

Optimize an entire project folder:

npx frontend-optimizer optimize ./src

This runs four steps:

1. Images — Convert PNG, JPEG, GIF, etc. to compressed WebP
2. Fonts — Self-host Google Fonts, add font-display: swap, preload key fonts
3. HTML — Add width/height, LCP fetchpriority="high", defer third-party scripts
4. Defer — Defer non-critical JavaScript and async-load non-critical CSS

Commands

| Command | Description | |---------|-------------| | optimize | Full pipeline (images + fonts + HTML + defer) | | images | Convert images to WebP | | fonts | Download and self-host web fonts | | html | Dimensions, LCP fetch priority, third-party scripts | | defer | Defer non-critical JS and CSS |

Examples

# Full optimization
npx frontend-optimizer optimize ./public

# Images only (aggressive compression)
npx frontend-optimizer images ./assets -q 65 --max-width 1920

# Self-host Google Fonts
npx frontend-optimizer fonts ./index.html

# HTML performance (LCP image, dimensions)
npx frontend-optimizer html ./index.html --lcp-image hero

# Defer analytics and non-critical assets
npx frontend-optimizer defer ./index.html

After global install, you can also use:

front-end optimize ./src

Features

Images (WebP)

• Converts PNG, JPG, JPEG, GIF, TIFF, BMP, AVIF → WebP
• Often reduces file size from MB to KB
• Optional resize (--max-width, --max-height)

Fonts

• Downloads fonts from Google Fonts, Bunny Fonts, and similar CDNs
• Self-hosts font files locally
• Adds font-display: swap to every @font-face
• Preloads key .woff2 files for faster rendering

HTML

• fetchpriority="high" on the LCP (hero) image
• Explicit width and height on images, videos, iframes, and embeds (reduces layout shift)
• Third-party scripts deferred (analytics, ads, tracking, etc.)

Defer non-critical assets

• Adds defer to analytics, chat, and tracking scripts
• Async-loads non-critical CSS (fonts, animations, icons) via the media="print" pattern

API (programmatic)

import {
  convertImages,
  localizeFonts,
  optimizeHtml,
  deferAssets,
} from "frontend-optimizer";

await convertImages("./photos", { quality: 75 });
await localizeFonts("./index.html");
await optimizeHtml("./index.html", { lcpImage: "hero" });
await deferAssets("./index.html");

Requirements

• Node.js 18+

Development

git clone https://github.com/Haseebcodejourney/frontend-optimizer.git
cd frontend-optimizer
npm install
npm run build
npm test

Publish updates

Bump version in package.json, then:

npm run build
npm test
npm publish

License

MIT © Hamza Haseeb