We all know the importance of a fast loading website. Just think back to the last time you went to a website on your phone and gave up after five or ten seconds of staring at a blank screen. And on a desktop or laptop, most people expect something useful to appear within 2-3 seconds.

There are many tools for measuring how long it takes to load a web page, including GTMetrix, WebPage Test and Chrome’s built-in audit tools. But there’s another factor that comes into play before the page even begins to load: Server Response Time (aka Time To First Byte or TTFB). This is the elapsed time from the browser’s initial request for a page until the first byte is delivered back from the server. It is a measure of both the efficiency of your hosting environment and the configuration of your site. Google recommends that this time be under 200ms (milliseconds).

Before the first byte

Here’s the basic sequence of events when a page is requested:

1. Resolve the domain name. Your browser needs the numeric IP address of your web host, in order to request the page. It will get this by requesting it from a DNS server, often at your Internet Service Provider.
2. Make a connection to the web server and request the page.
3. If the page is being redirected, reconnect and request the new URL.
4. Make a secure connection, if the HTTPS protocol is being used. 
5. Wait for the web server to start delivering the page.

Things the web host can control

Your web host should have an efficient network architecture and computers with enough performance to keep things moving right along. Some hosting items that can affect response time:

• Distributed DNS. By storing your domain’s IP information on multiple DNS servers around the world, the first step in the process can be shortened by a few milliseconds.
• Adequate CPU resources. If you use shared hosting (as most of us do), you are sharing CPU time with everyone else on the server. When hosting companies oversell their servers, CPUs become overloaded and performance suffers.
• Hard drive speed. Again, shared hosting has many separate processes accessing a server’s hard drives simultaneously. Hosts with the best performance are using solid state drives (SSD) with no moving parts, to speed up access times.
• Current versions of server-side languages and databases. WordPress and other CMS systems make use of programming languages and databases connected to the server. The latest versions of these resources are considerably faster than older versions.

Things you can do

How your site is configured has a big impact on how quickly it delivers that first byte. Some of the items under your control include:

• Server-side caching. Pages delivered by WordPress and other CMS systems are constructed by filling templates with content stored in a database, and that takes time. A caching system also stores these pages as static HTML, which don’t require trips to the database. These HTML pages are rebuilt each time you make a change to your site. Server caching is usually enabled and controlled using a plugin.
• Browser caching. The fastest loading page is one that your browser already has. Most server-side caching programs add code to each page instructing the browser to store the page on the visitor’s computer for future use.
• Use the most current version of PHP (for WordPress) available from your host. You can either ask tech support to make this change or check the control panel in your account. Look for something like “Select PHP Version”.
• Minimize connections to 3rd party sites. Embedding widgets like Google Maps or Facebook feeds can delay the delivery of your page until connections are made to those services.

Test, test, test

Want to see how well your site is doing? A nice, simple server response time checker is available from Bitcatcha. It makes page requests from 10 different locations around the world, averages the response times and gives you a score. Anything less than B+ would be cause for concern. Test your site, test your friend’s sites and let me know what you find.

Until next week.