Document request latency
The Document request latency audit measures the time it takes to request and download the initial HTML document for a page. This value is crucial, as the browser cannot start rendering or loading other resources, until it receives the HTML. It mainly measures: page redirection, initial server response time, text compression; to identify bottlenecks.
Your first network request is the most important. Reduce its latency by avoiding redirects, ensuring a fast server response and enabling text compression.
Understanding document request latency
There are three essential topics that complete the scope of this audit:
Avoid multiple page redirects
Redirects occur when accessing a non-canonical URL: www.example.com → example.com. Or a mobile version, such as: example.com → m.example.com. Each redirect causes a delay. It is essential to avoid unnecessary redirects and use responsive design instead of separate mobile versions.
Reduce initial server response time
This is the time it takes for the first byte of HTML to reach the visitor’s browser from your server. Your website's slowest tasks must be identified and optimized, adjust database queries, and consider upgrading your server, as using a CDN to reduce latency.
Enable text compression
Text compression reduces file sizes by using algorithms like Gzip or Brotli, speeding up page load times. Enabling compression, minimizes bandwidth usage and improves performance for users on slow networks. Most servers and CDNs support it with simple configuration.
How to improve the Document request latency
WP Rocket has two automatic features to help on this matter:
- Page caching: It greatly reduces the server response time, by serving fast HTML pages.
- Text compression: On Apache/LiteSpeed servers, WP Rocket automatically adds GZIP compression rules in your .htaccess file using the mod_deflate module.