# Gzip & Brotli size estimator — no upload

> Estimate the gzip and Brotli compressed size of text or code to see how it'll transfer over the wire, in your browser. Nothing is uploaded.

Paste text or code to see its gzip and Brotli compressed size — the size that actually travels over the wire — computed in the browser with no upload.

Bundle-size budgets are about transfer size, not raw bytes. Estimating gzip and Brotli output tells you what a chunk of JS or CSS really costs to ship, so you can judge whether a change is worth it.

To shrink code first, use the code formatter's minify mode; to optimize SVGs, the SVG optimizer.

## How to

1. **Paste content.** Paste the text, JS, or CSS to measure.
2. **Compress.** See gzip and Brotli sizes and the ratio.
3. **Compare.** Judge the transfer size versus the raw size.

## FAQ

### Why measure gzip/Brotli size instead of raw size?

Servers compress text assets before sending, so the compressed size is what users actually download. It's the number that matters for load performance.

### Is Brotli always smaller than gzip?

Usually, especially for text, which is why it's preferred where supported. The estimator shows both so you can compare for your content.

### Is my content uploaded?

No. Compression is done in the browser, so your code stays in the tab.


## Related tools

- [Format & minify](https://www.safepaper.app/dev/code-formatter)
- [SVG optimize](https://www.safepaper.app/media/svg-optimize)
- [Base64](https://www.safepaper.app/dev/base64)
- [JSON toolkit](https://www.safepaper.app/dev/json-toolkit)

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Canonical HTML: https://www.safepaper.app/dev/gzip
Markdown: https://www.safepaper.app/dev/gzip.md

There is no upload endpoint — your files are processed in this browser tab. Open your network tab and check.