How does Cloudflare compress content?

Cloudflare compresses content in two ways: between Cloudflare and your website visitors and between Cloudflare and your origin server.

​​ Compression between Cloudflare and website visitors

In addition to Cloudflare’s default caching behavior and auto minification of CSS, JavaScript, and HTML content, Cloudflare supports Gzip and Brotli compression when delivering content to website visitors.

If supported by visitors’ web browsers, Cloudflare will return Gzip or Brotli-encoded responses for the following content types:

text/html
text/richtext
text/plain
text/css
text/x-script
text/x-component
text/x-java-source
text/x-markdown
application/javascript
application/x-javascript
text/javascript
text/js
image/x-icon
image/vnd.microsoft.icon
application/x-perl
application/x-httpd-cgi
text/xml
application/xml
application/rss+xml
application/vnd.api+json
application/x-protobuf
application/json
multipart/bag
multipart/mixed
application/xhtml+xml
font/ttf
font/otf
font/x-woff
image/svg+xml
application/vnd.ms-fontobject
application/ttf
application/x-ttf
application/otf
application/x-otf
application/truetype
application/opentype
application/x-opentype
application/font-woff
application/eot
application/font
application/font-sfnt
application/wasm
application/javascript-binast
application/manifest+json
application/ld+json
application/graphql+json
application/geo+json

Cloudflare’s global network can deliver content to website visitors using Gzip compression, Brotli compression, or no compression, according to the values visitors provide in the Accept-Encoding request header.

For responses with error status codes, Cloudflare will only compress responses if their error status code is 403 or 404. For successful response status codes, Cloudflare will only compress responses if their status code is 200. Responses with other status codes will not be compressed.

Enterprise customers can override Cloudflare’s default compression behavior using Compression Rules.

​​ Content compression from origin servers to the Cloudflare network

When requesting content from your origin server, Cloudflare supports Gzip compression, Brotli compression, or no compression.

If your origin server responds to a Cloudflare request using Gzip/Brotli compression, we will keep the same compression in the response sent to the website visitor if:

• You include a Content-Encoding header in your server response mentioning the compression being used (gzip or br).
• The visitor browser (or client) supports the compression algorithm.
• You do not enable Cloudflare features that change the response content (refer to Notes about end-to-end compression for details).

Cloudflare’s reverse proxy can also convert between compressed formats and uncompressed formats. Cloudflare can receive content from your origin server with Gzip or Brotli compression and serve it to visitors uncompressed (or vice versa), independently of caching.

If you do not want a particular response from your origin to be encoded with Gzip/Brotli when delivered to website visitors, you can disable this by including a cache-control: no-transform HTTP header in the response from your origin web server.

​​ Notes about end-to-end compression

Even when using the same compression algorithm end to end (between your origin server and Cloudflare, and between the Cloudflare global network and your website visitor), Cloudflare will need to decompress the response and compress it again if you enable any of the following options for the request:

• Email Address Obfuscation
• Rocket Loader
• Server Side Excludes (SSE)
• Mirage
• HTML Minification (you can minify JavaScript and CSS without any impact)
• Automatic HTTPS Rewrites
• Polish

To disable these features for specific URI paths, create a Configuration Rule.

Additionally, Cloudflare Fonts also requires Cloudflare to decompress the response and compress it again, and cannot be disabled through Rules at this time.