Compression

This guide covers the Layer0 response compression support.

Accept-Encoding#

When requesting data via HTTP from the Layer0 servers, browsers include the accept-encoding header to indicate which data compression formats the browser supports. Modern browsers accept multiple compression formats, Accept-Encoding Header Details are here. This header is required by Layer0 to trigger compression of responses.

Layer0 supports#

• gzip for all versions
• br (Brotli) for versions >= 4.11.0

Enabling Brotli compression#

To enable Brotli (br) compression you need to ensure your project uses a version of @layer0 >= 4.11.0. To upgrade @layer0 to the latest version in your project use 0 use latest and redeploy your project.

What is Compressed?#

When Layer0 servers receive a request they inspect the accept-encoding header. The following logic is used to determine response compression:

• If the response is not a compressible type, return uncompressed.
• Else if br is found and the @layer0 version is >= 4.11.0 then compress the response using Brotli.
• Else if gzip is found, then compress the response using gzip.
• Else no compression is used.

Compressible Types#

A response is considered compressible if the content-type contains one of these strings:

• text/html
• application/x-javascript
• text/css
• application/javascript
• text/javascript
• application/json
• application/vnd.ms-fontobject
• application/x-font-opentype
• application/x-font-truetype
• application/x-font-ttf
• application/xml
• font/eot
• font/opentype
• font/otf
• image/svg+xml
• image/vnd.microsoft.icon
• text/plain
• text/xml

or the url ends in one of these file extensions:

• .css
• .js
• .html
• .eot
• .ico
• .otf
• .ttf
• .json
• .svg