WebSize 📏

A Deno library for measuring webpage sizes and render times. Get accurate measurements of:

• Raw HTML size
• Rendered page size (after JavaScript execution)
• Network transfer size
• Render time

Features

• 🚀 Simple static method for quick measurements
• ⚙️ Configurable options for detailed control
• 📊 Detailed size metrics and timing
• 🌐 Supports custom user agents
• 🔄 Multiple wait conditions for accurate rendering
• 📝 Optional verbose logging

Installation

# Import from JSR
import { WebSize } from "jsr:@varandas/websize";

Quick Start

// Quick single measurement
const result = await WebSize.measure("https://example.com");
console.log(result);
// {
//   rawSizeKB: 15.2,
//   renderedSizeKB: 25.7,
//   renderTimeSeconds: 1.2,
//   transferSizeMB: 0.35
// }

Advanced Usage

With Custom Options

const result = await WebSize.measure("https://example.com", {
  waitUntil: "networkidle2", // Wait for network to be idle
  verbose: true, // Enable detailed logging
  userAgent: "Custom Agent", // Set custom user agent
});

Multiple Measurements

// Create a reusable instance
const webSize = new WebSize({
  verbose: true,
  waitUntil: "load",
});

// Measure multiple sites
const sites = ["https://deno.land", "https://example.com"];
for (const site of sites) {
  const result = await webSize.calculatePageSize(site);
  console.log(`${site}: ${result.renderedSizeKB}KB`);
}

API Reference

WebSize Class

Constructor Options

Option	Type	Default	Description
userAgent	string	Chrome/122...	Browser user agent string
waitUntil	WaitUntil	networkidle2	Page load condition
verbose	boolean	false	Enable console logging

Wait Conditions

• load: Wait for load event
• networkidle0: No network connections for 500ms
• networkidle2: ≤ 2 network connections for 500ms
• none: Don't wait

Result Object

interface PageSizeResult {
  rawSizeKB: number; // Size of raw HTML
  renderedSizeKB: number; // Size after JavaScript
  renderTimeSeconds: number; // Processing time
  transferSizeMB: number; // Network transfer size
}

Development

# Run tests
deno task test

# Run example
deno task example

# Type check
deno task check

Under the Hood

WebSize uses Astral as its headless browser engine to:

1. Fetch raw HTML content
2. Execute JavaScript
3. Measure rendered page size
4. Track network transfers

License

MIT License - © André Varandas

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