Gzip Compression

Basic Gzip Configuration

http {
    # Enable gzip
    gzip on;

    # Compression level (1-9, higher = more compression)
    gzip_comp_level 5;

    # Minimum size to compress
    gzip_min_length 256;

    # Compress for proxied requests
    gzip_proxied any;

    # Vary header for caching
    gzip_vary on;

    # MIME types to compress
    gzip_types
        text/plain
        text/css
        text/xml
        text/javascript
        application/json
        application/javascript
        application/xml
        application/xml+rss
        application/x-javascript
        image/svg+xml;
}

Optimized Configuration

# /etc/nginx/snippets/gzip.conf

gzip on;
gzip_comp_level 5;
gzip_min_length 256;
gzip_proxied any;
gzip_vary on;

# Disable for old browsers
gzip_disable "msie6";

# Buffer size
gzip_buffers 16 8k;

# HTTP version
gzip_http_version 1.1;

# Comprehensive MIME types
gzip_types
    application/atom+xml
    application/geo+json
    application/javascript
    application/json
    application/ld+json
    application/manifest+json
    application/rdf+xml
    application/rss+xml
    application/vnd.ms-fontobject
    application/wasm
    application/x-javascript
    application/x-web-app-manifest+json
    application/xhtml+xml
    application/xml
    font/eot
    font/otf
    font/ttf
    image/bmp
    image/svg+xml
    text/cache-manifest
    text/calendar
    text/css
    text/javascript
    text/markdown
    text/plain
    text/vcard
    text/vnd.rim.location.xloc
    text/vtt
    text/x-component
    text/x-cross-domain-policy
    text/xml;

Use in Server

server {
    listen 443 ssl http2;
    server_name example.com;

    include snippets/gzip.conf;

    # ... rest of config
}

Disable for Specific Locations

# Don't compress already compressed files
location ~* \.(gz|zip|rar|7z)$ {
    gzip off;
}

# Don't compress images (already compressed)
location ~* \.(jpg|jpeg|png|gif|webp)$ {
    gzip off;
}

Pre-compressed Files

# Serve pre-compressed .gz files
gzip_static on;

# Files must exist: style.css and style.css.gz
location ~* \.(css|js)$ {
    gzip_static on;
    expires 30d;
}

# Create pre-compressed files
gzip -k -9 /var/www/html/css/style.css
gzip -k -9 /var/www/html/js/app.js

Testing Compression

# Check if gzip is working
curl -H "Accept-Encoding: gzip" -I https://example.com/style.css

# Should show: Content-Encoding: gzip

# Compare sizes
curl -so /dev/null -w '%{size_download}' https://example.com/style.css
curl -sH "Accept-Encoding: gzip" -o /dev/null -w '%{size_download}' https://example.com/style.css

Compression Levels

For most cases, level 5 provides the best balance of CPU usage and compression ratio.