What is GZIP Compression and how to enable it (Step by Step)

Consider shipping a large package through the mail, it takes longer, costs more, and is occasionally delayed. Consider if you could reduce the size of the package while retaining all of its contents. That is exactly what GZIP compression performs to your website’s files.

Whether you’re building your first website, managing a big blog, or running a large online application, GZIP compression may significantly increase your site’s loading time. Faster websites result in happier visitors, higher SEO ranks, and fewer bandwidth expenses.

In this article, you’ll learn what GZIP compression is, how it works under the hood, and how to activate it step by step – whether you’re hosting with Cloudways or another platform.I’ll also share tips to troubleshoot and optimize your website’s speed further.

Understanding GZIP Compression

At its core, GZIP is a lossless compression algorithm. That means it reduces the size of your files without losing any data. It’s like zipping a folder on your computer – the files inside stay intact but take up less space.

How Does GZIP Work?

Pattern Detection (LZ77 Algorithm):

GZIP scans your files (HTML, CSS, JavaScript, XML, etc.) for repeated strings or patterns. Instead of sending the same text multiple times, it replaces repeats with references to the first occurrence. This reduces redundancy.

Encoding (Huffman Coding):

After identifying patterns, GZIP assigns shorter binary codes to frequently used characters and longer codes to rare ones, optimizing file size even more.

Headers and Integrity Checks:

GZIP adds a small header to indicate compression and a footer for checksums to ensure the file hasn’t been corrupted during transmission.

Why Does This Matter?

Because your website files become smaller, they travel faster over the internet. This reduces load times, bandwidth usage, and server load – all critical factors for a smooth user experience.

Is GZIP Compression Enabled by Default on Cloudways?

Great question! Cloudways enables GZIP compression by default on all their managed servers. This means as soon as you launch your website on Cloudways, your files are automatically compressed and delivered faster to your visitors.

Cloudways uses a powerful server stack (Apache + Nginx + PHP-FPM) optimized for speed, and GZIP fits perfectly into this setup. You don’t usually need to do anything extra.

However, if you’ve customized your server configuration or want to verify GZIP is working correctly, keep reading – I’ll show you how to check and enable it manually if needed.

How to Check if GZIP Compression is Enabled on Your Website?

Before making changes, it’s smart to confirm if GZIP is active.

Method 1: Using Online Tools

• Visit a free tool like Check GZIP Compression.
• Enter your website URL.
• The tool will tell you if GZIP is enabled and show the compression ratio. We have tested the Cloudways application to perform this test and you can see it’s enabled.

Method 2: Using Browser Developer Tools

• Open your website in Google Chrome.
• Press F12 to open Developer Tools.
• Click the Network tab.
• Reload the page.
• Click on the main HTML file (usually the first request).
• Look under Headers > Response Headers for content-encoding: gzip.
• If you see gzip there, your server is compressing files correctly.

Step-by-Step Guide to Enable GZIP Compression

If your site isn’t compressed or you want to customize it, here’s how to enable GZIP on different server environments.

For Apache Servers (.htaccess)

Most shared hosts and many Cloudways apps use Apache or Apache+Nginx. The .htaccess file controls server behavior here.

File path: Your website’s root directory, often /public_html/.htaccess or /app/public/.htaccess.

Why do we need it in .htaccess?

It’s a configuration file Apache reads for directory-specific rules.

Steps:

• Access the .htaccess file
• Use your hosting platform to connect SFTP with SFTP Client. If you are a Cloudways user then Cloudways Platform > Applications > Your App > Access Details > SFTP to connect with a client like FileZilla.
• Navigate to the root folder (public_html or app/public).
• Backup .htaccess file in case you want to undo the changes or to keep a copy of the original file intact.
• Download a copy to your local machine before editing.
• Edit .htaccess file by opening .htaccess in a text editor.
• Add the following code at the bottom:

<IfModule mod_deflate.c>

# Compress HTML, CSS, JavaScript, Text, XML, fonts

AddOutputFilterByType DEFLATE text/html text/plain text/xml text/css application/javascript application/x-javascript application/xml application/xhtml+xml application/rss+xml application/atom+xml image/svg+xml application/font-woff application/font-woff2

# Fix for old browsers

BrowserMatch ^Mozilla/4 gzip-only-text/html

BrowserMatch ^Mozilla/4\.0[678] no-gzip

BrowserMatch \bMSIE !no-gzip !gzip-only-text/html

Header append Vary User-Agent

</IfModule>

Why is this code needed?

• mod_deflate is Apache’s module for compression.
• AddOutputFilterByType tells Apache which file types to compress.
• BrowserMatch lines fix known bugs in older browsers.
• Header append Vary User-Agent ensures proxies and CDNs cache compressed and uncompressed versions correctly.
• Save and upload the .htaccess file back.
• Test compression using the methods in section 4.

For Nginx Servers (nginx.conf)

Nginx is popular for high-performance sites and Cloudways uses it as a reverse proxy in their Stack.

• File path: Usually /etc/nginx/nginx.conf or /etc/nginx/sites-available/your-site.conf.

Steps:

• Access your server via SSH (Cloudways provides SSH access).
• Open the nginx config file with a command like:

sudo nano /etc/nginx/nginx.conf

• Locate the http {} block and add or update these lines:

gzip on;

gzip_disable "msie6"; # Disable for old IE6 browsers

gzip_vary on; # Enable Vary header for proxies

gzip_proxied any; # Compress requests coming through proxies

gzip_comp_level 5; # Compression level (1-9), 5 is a good balance

gzip_buffers 16 8k; # Buffer settings

gzip_min_length 256; # Minimum file size to compress

gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript image/svg+xml;

• Save and exit (Ctrl+O, Enter, Ctrl+X in nano).
• Reload Nginx to apply changes:

sudo systemctl reload nginx

• Test your site for GZIP as before.

Using WordPress Plugins (No Coding Needed)

If you’re on WordPress and prefer a no-code approach:

• WP Fastest Cache or W3 Total Cache plugins have easy GZIP enable options.
• After installing, go to plugin settings and enable GZIP compression with one click.
• This method works regardless of your hosting but is especially handy on shared hosts.

Common Issues and How to Troubleshoot GZIP Compression

1. GZIP not working after enabling?

• Check if mod_deflate is enabled on Apache (a2enmod deflate on Debian/Ubuntu).
• Make sure you edited the correct .htaccess file (sometimes multiple exist).
• For Nginx, confirm config syntax with nginx -t before reload.

2. Compression causing site errors?

• Disable compression for certain file types (like images compression or videos).
• Check for conflicting plugins or server rules.

3. Old browsers not rendering properly?

• The BrowserMatch lines in Apache fix most issues.
• For Nginx, gzip_disable “msie6”; disables compression for IE6.

Extra Tips to Maximize Website Speed on Cloudways

• Leverage Cloudways’ built-in caching: Varnish, Memcached, and Redis cache dynamic content for lightning-fast delivery.
• Use Cloudways Cloudflare CDN: Distribute compressed files globally for minimal latency.
• Optimize images: Use tools like TinyPNG or plugins like Smush to reduce image sizes.
• Minify CSS and JavaScript: Combine and minify files to reduce HTTP requests.
• Enable Browser Caching: Store static resources in visitors’ browsers for faster repeat visits.
• Monitor Performance: Cloudways provides real-time server monitoring to catch bottlenecks early.

Conclusion

GZIP compression is a fundamental, powerful technique that every website owner should understand and use. It reduces file sizes dramatically, speeds up your website, saves bandwidth, and improves SEO – all with minimal effort.

On Cloudways, you’re already benefiting from GZIP by default, thanks to their optimized server stack. But knowing how to check, enable, and troubleshoot GZIP yourself empowers you to keep your site running at top speed no matter where you host.

Combine GZIP with Cloudways’ advanced caching, SSD storage, and CDN to deliver a seamless, blazing-fast experience your visitors will love.

Salwa Mujtaba

Salwa Mujtaba is a Technical Content Writer at Cloudways. With a strong background in Computer Science and prior experience as a team lead in Cloudways Operations, she brings a deep understanding of the Cloudways Platform to her writing. Salwa creates content that simplifies complex concepts, making them accessible and engaging for readers. When she's not writing, you can find her enjoying good music, reading a book, or spending quality time with her family.

Get Connected on: Twitter Community Forum