Bundle Size Calculator – Web App JavaScript, CSS & Image Bundle Size Estimator
Optimize your web application for mobile performance with our free Bundle Size Calculator. Calculate total web app bundle size and estimated gzip compressed size for JavaScript, CSS, and image assets. This JavaScript bundle size and gzip compression calculator is essential for developers building mobile-optimized websites and progressive web apps where bundle size directly impacts load performance.
Bundle Size Calculator
Calculate web app bundle size and gzip compressed size for mobile optimization
Bundle Size Calculator Features
- Calculates web app bundle size from JavaScript, CSS, image, and font components
- Estimates the gzip-compressed bundle size for optimized delivery estimation
- Assigns a performance grade based on total bundle size for mobile optimization
- Useful for web developers optimizing Progressive Web Apps for mobile browsers
- Displays raw total, gzip-compressed size, and a grade label in the results
- Helps identify which component type contributes most to bundle bloat
How to Use Bundle Size Calculator
- Enter the JavaScript bundle size in KB (e.g., 300) in the “JavaScript” field
- Enter the CSS size in KB (e.g., 80) in the “CSS” field
- Enter the images total size in KB (e.g., 500) in the “Images” field
- Enter the fonts size in KB (e.g., 120) in the “Fonts” field
- Click the Calculate button
- View total bundle size, gzip-compressed size, and performance grade in the results
- Click Reset to calculate for a different bundle configuration
Frequently Asked Questions
Web app bundle size is the total file size of JavaScript, CSS, fonts, and images delivered to the browser. Smaller bundles load faster, especially on mobile networks. Our bundle size calculator estimates total and compressed sizes.
Gzip typically compresses JavaScript by 60–70% and CSS by 70–80%. Our gzip compression calculator estimates compressed size by applying typical compression ratios to your entered raw bundle sizes.
Google recommends keeping JavaScript bundle size under 170 KB (compressed). Above 300 KB causes noticeable performance degradation on mobile devices. Use our bundle size calculator to audit your total JS payload.
Large bundles increase parse time, execution time, and network transfer duration. On 3G connections, every extra 100 KB adds approximately 0.5–1 second of load time. Optimize using our web app bundle calculator.
Code splitting, tree shaking, lazy loading, and minification reduce JavaScript bundle size significantly. Tools like webpack, Rollup, and Vite automate these optimizations. Use our calculator to measure improvements.
Yes, images are a major part of web app bundle size. Our bundle size calculator includes separate fields for image assets to give a complete picture of total payload delivered to mobile browsers.
Brotli compression outperforms gzip by 15–20% additional size reduction. Our gzip compression calculator uses standard gzip ratios, but Brotli-enabled servers will achieve even smaller bundle sizes in production.
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