---
title: "Gzip / Brotli compression check — Lemwatch Help"
description: "Verifies your server compresses HTML, CSS, JS, and JSON responses — up to 80% payload reduction that costs nothing to enable."
canonical: "https://lemwatch.com/help/gzip-brotli-compression-check"
source: "https://lemwatch.com"
---

# Gzip / Brotli compression check

> Verifies your server compresses HTML, CSS, JS, and JSON responses — up to 80% payload reduction that costs nothing to enable.

## Quick answer

 We send Accept-Encoding: br, gzip, deflate and check which encoding your server picks. Uncompressed text responses fail.

## What it checks

- HTML, CSS, JS, JSON, SVG served compressed

- Brotli preferred (bonus)

- Compression ratio ≥60%

- Compression NOT applied to images/video (which are already compressed)

## Where to find it in Lemwatch

 **Site details → Performance → Compression.**

## How to fix

- Enable gzip in your web server config.

- Add Brotli for another 15-20% savings.

- Set compression on text/* and application/json, javascript, xml.

- Re-run the check.

## FAQ

### Should I compress at the CDN or origin?

 CDN — cached compressed variants are cheapest.

### Is Brotli safe?

 Yes — supported by every modern browser since 2017.

## Related

- Performance budgets

- Core Web Vitals

- Cache-Control header check


## Related

- [Help centre](https://lemwatch.com/help)
- [Setting Performance Budgets](https://lemwatch.com/help/performance-budgets)
- [Core Web Vitals Explained](https://lemwatch.com/help/core-web-vitals)
- [Cache-Control header check](https://lemwatch.com/help/cache-control-header-check)
- [Canonical tag check](https://lemwatch.com/help/canonical-tag-check)
- [Lemwatch pricing](https://lemwatch.com/pricing)
- [Health Alert Threshold](https://lemwatch.com/help/health-alert-threshold)
- [Guided Onboarding Tour](https://lemwatch.com/help/guided-tour)