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Analysis Results
Bundle Size Estimator
Analyze JavaScript bundle sizes and optimize your dependencies
Key Features
Size Analysis
Minified and gzipped size estimates
Load Time
Estimated download time
Lazy Loading
Identify lazy-loadable packages
Comparison
Compare multiple packages
Export Reports
Download analysis results
Optimization
Get improvement suggestions
Understanding Bundle Sizes
Bundle size directly impacts your application's performance. Smaller bundles load faster, improving user experience and SEO rankings.
Size Metrics Explained
Minified Size
Code with unnecessary characters removed. Reduces file size by 30-50%.
Gzipped Size
Minified code compressed with gzip. Further reduces by 60-70%.
Load Time
Estimated time to download bundle on 4G connection.
Lazy Load Savings
Potential size reduction by lazy loading non-critical code.
Frequently Asked Questions
What is bundle size?
Bundle size is the total size of your JavaScript code after minification and compression.
What's the difference between minified and gzipped?
Minified removes unnecessary characters. Gzipped compresses the minified code further for transfer.
How does lazy loading help?
Lazy loading defers loading non-critical code until needed, reducing initial bundle size.
What's a good bundle size?
Aim for under 100 KB gzipped for optimal performance. Larger bundles increase load times.
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Use ToolRelated guides
Read the how-to, then come back to this tool when you are ready to run it locally.
- A Pre-Launch Checklist for a New Web PageTitle tags, meta description, Open Graph, SERP snippet, favicon, bundle weight, lazy-load, and a first accessibility pass - before you ship, without a login.
- How to Convert Bytes, Bits, KB, MB, and GBSI vs binary prefixes for storage. Convert locally while debugging downloads.
- Best CSS and Frontend Design ToolsColor palettes, CSS animation previews, favicons, patterns, bundle size, and screen-reader checks - all in the browser.