Zstandard (zstd)

The module adds support for Zstandard compression of responses, both dynamic (on-the-fly) and static (precompressed files). Compared to gzip, zstd offers higher compression and decompression speeds at comparable or better compression ratios.

The module consists of two components:

• http_zstd_filter — for compressing responses dynamically;

• http_zstd_static — for serving precompressed files.

Module Loading

Enable the modules in the main{} context:

load_module modules/ngx_http_zstd_filter_module.so;
load_module modules/ngx_http_zstd_static_module.so;

Example Configuration

server {
    listen 80 default_server;

    zstd_types text/plain text/css;
    zstd_min_length 256;         # Minimum response size to compress
    zstd_comp_level 3;           # Compression level (1–22)

    # Dynamic compression for static files
    location / {
        zstd on;
        root /usr/share/angie/html;
    }

    # Dynamic compression for backend responses
    location /bk/ {
        zstd on;
        proxy_pass http://127.0.0.1:8081/;
    }

    # Serving precompressed .zst files
    location /static/ {
        zstd_static on;
        root /usr/share/angie;
    }
}

server {
    listen 8081;
    location / {
        root /usr/share/angie/html;
        index index.html;
    }
}

How It Works

You can combine dynamic (zstd on) and static (zstd_static on) compression. In this case, the server will first look for a precompressed .zst file. If it doesn't exist, it will compress the response dynamically.

Compression is only performed when the Accept-Encoding header includes zstd, for example:

Accept-Encoding: gzip, zstd

If compression is applied or a precompressed file is found, the following response header is added:

Content-Encoding: zstd

More Information

Full documentation and source code are available at: tokers/zstd-nginx-module