How to see your svg's real transfer size after gzip and brotli compression
- Step 1Drop your SVG — Drag your SVG file onto the tool. You can also paste SVG source code directly for instant analysis.
- Step 2Read the compression breakdown — The tool shows: raw size, gzip estimated size (using DeflateRaw), brotli estimated size, and the compression ratio percentage for each algorithm.
- Step 3Identify savings opportunities — If compression ratio is below 60%, your SVG may benefit from minification first (more repetitive structure compresses better). Run the SVG Minifier, then re-estimate.
Frequently asked questions
How accurate is the gzip estimate?+
The tool uses the browser's native CompressionStream API with the deflate-raw algorithm, which is the same underlying engine as gzip compression. The estimate is essentially exact for gzip.
How accurate is the brotli estimate?+
The browser CompressionStream supports brotli (in Chrome and Edge). On those browsers, the brotli estimate is exact. On Firefox and Safari, it's estimated from gzip with a typical 15–20% improvement factor.
Do web servers compress SVG files automatically?+
Most do, if the SVG is served with the correct MIME type (image/svg+xml) and the server has text compression enabled. Check your server config: Apache (mod_deflate), Nginx (gzip on), Cloudflare (auto).
Why is my brotli estimate much better than gzip?+
Brotli has a larger dictionary and more efficient encoding — it typically beats gzip by 15–25% on SVGs. Both algorithms exploit SVG's repetitive XML structure very effectively.
Privacy first
Every JAD SVG tool runs entirely in your browser using the DOM API and Canvas. Your SVG files never leave your device — verified by zero outbound network requests during processing.