+++
date = 2022-12-01
title = "Enable GZIP Compression in Nginx"
description = ""
draft = false
+++

# Text Compression

Text compression allows a web server to serve text-based resources faster than
uncompressed data. This can speed up things like First Contentful Paint, Tie to
Interactive, and Speed Index.

# Enable Nginx Compression with gzip

In order to enable text compression on Nginx, we need to enable it within the
configuration file:

```sh
nano /etc/nginx/nginx.conf
```

Within the `http` block, find the section that shows something like the block
below. This is the default gzip configuration I found in my `nginx.conf` file on
Alpine Linux 3.17. Yours may look slightly different, just make sure that
you're not creating any duplicate gzip options.

``` conf
# Enable gzipping of responses.
#gzip on;

# Set the Vary HTTP header as defined in the RFC 2616. Default is 'off'.
gzip_vary on;
```

Remove the default gzip lines and replace them with the following:

``` conf
# Enable gzipping of responses.
gzip on;
gzip_vary on;
gzip_min_length 10240;
gzip_proxied expired no-cache no-store private auth;
gzip_types text/plain text/css text/xml text/javascript application/x-javascript application/xml;
gzip_disable "MSIE [1-6]";
```

# Explanations of ngx~httpgzipmodule~ Options

Each of the lines above enables a different aspect of the gzip response for
Nginx. Here are the full explanations:

- `gzip` -- Enables or disables gzipping of responses.
- `gzip_vary` -- Enables or disables inserting the "Vary: Accept-Encoding"
  response header field if the directives gzip, gzip~static~, or gunzip are
  active.
- `gzip_min_length` -- Sets the minimum length of a response that will be
  gzipped. The length is determined only from the "Content-Length" response
  header field.
- `gzip_proxied` -- Enables or disables gzipping of responses for proxied
  requests depending on the request and response. The fact that the request is
  proxied is determined by the presence of the "Via" request header field.
- `gzip_types` -- Enables gzipping of responses for the specified MIME types in
  addition to "text/html". The special value "*" matches any MIME type
  (0.8.29). Responses with the "text/html" type are always compressed.
- `gzip_disable` -- Disables gzipping of responses for requests with
  "User-Agent" header fields matching any of the specified regular
  expressions.
    - The special mask "msie6" (0.7.12) corresponds to the regular expression
      "MSIE [4-6].", but works faster. Starting from version 0.8.11, "MSIE
      6.0; ... SV1" is excluded from this mask.

More information on these directives and their options can be found on the
[Module
ngx~httpgzipmodule~](https://nginx.org/en/docs/http/ngx_http_gzip_module.html)
page in Nginx's documentation.