Brotli is not working over non-https

Why brotli is not supported over HTTP connections, and what you can do to get around the problem on local servers.

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By. Jacob

Edited: 2023-08-09 01:09

By default, Brotli is not included in the accept-encoding header Google Chrome, Firefox and Safari, for http connections; apparently this is due to issues with web proxies that misbehave when they encounter non deflate/gzip Content-Encoding.

This is causing problems when developers need to test their brotli implementations on local servers, since those will often be running on HTTP rather than HTTPS.

There is a couple of nice solutions to this problem; one is to modify the accept-encoding header using a browser plugin, and another, my favorite, is to test implementations with cURL from a terminal:

curl -H "accept-encoding: br" --HEAD http://example.com/

So, the reason why your Browser does not include br in its accept-encoding over clean HTTP connections is, most likely, not because it does not support Brotli; you can still do your testing with tools such as cURL from a terminal.

Alternatively, you can also install a self-signed certificate on your local server. The problem with this is that the browser will complain that the connection is not secure.