What Is Server Response Time? How to Test and Improve Server Response Time

If you want to speed up your website, you might have come across a suggestion to "reduce server response time".

That might have thrown up a few immediate questions: what is server response time? How do I test mine? How do I actually go about reducing it?

In this post, we're going to answer all of those questions for you. By the end, you'll understand everything you need to know about server response time. Here's what we'll cover:

  • A deeper look at what server response time is and why it's important.
  • How to run a server response time test.
  • How to reduce server response time.

Let's get started!

What Is Server Response Time?

Server response time refers to the time it takes between a client making a request to your website's server and your server responding with the first byte of information.

Most of the time, the "client" in this situation will be a website visitor's web browser.

When someone visits your site, their web browser needs to send a request to your website's server. This "request" is essentially the browser asking for the HTML and other files that it needs to render the webpage for the visitor. Server response time measures how long it takes for your server to start responding with that information.

Server response time is important for web performance because a slow server response time means it will take longer for your page to load.

What's a Good Server Response Time?

In the next section, we'll show you how to run a server response time test. But before we do that, let's go over some context for understanding the times that you'll see in those test tools.

Basically - what is a "good" server response time?

Well, there's some debate here, but Google recommends that your server response time is under 200 ms.

Under 200 ms is very good. However, this is a pretty strict number and most sites will fail to reach this number. According to Littledata's analysis of 3,973 websites, the average server response time of that sample was 530 ms.

In general, anything around ~500 ms is still fine. Faster would be better, but 500 ms is still well within the normal range.

However, if your server response time is around one second (1,000 ms) or slower, you'll definitely want to work to reduce it. We'll share some tips to reduce server response time later in this post.

How to Run a Server Response Time Test

Server response time is measured using a metric called time to first byte, or TTFB for short.

To run a server response time test, you can use any tool that allows you to measure TTFB. Let's go through some of the best options...

WebPageTest Server Response Time Test

WebPageTest is a full-service website performance test tool that includes TTFB as one of its performance metrics.

To get started, go to the site and configure your test conditions.

We recommend choosing a server test location that's near to your target audience. For example, if you target a UK audience, choose a UK test server such as London.

For the connection, we recommend choosing FIOS to simulate real-world conditions.

Finally, to get more accurate results, we recommend configuring WebPageTest to run nine separate tests. It will then automatically display the median value of all nine tests.

WebPageTest configuration screen

Once you run the test, look at the First Byte column to see your server response time:

WebPageTest performance results screen

Geekflare Server Response Time Test

Geekflare offers another easy-to-use tool for testing TTFB. All you do is plug in the URL to your site and hit Test TTFB.

Then, you'll get results for three different locations:

  • New York, USA
  • London, UK
  • Bangalore, India

Note that Geekflare will show you your slowest time based on the three locations that it tests. However, you should focus on the test location that's closest to your target audience.

For example, we're a UK-based host, so we primarily target a UK and European audience. For our purposes, the Krystal homepage's 18 ms TTFB from the London test server is the most relevant.

Geekflare TTFB test results screen

KeyCDN Server Response Time Test

KeyCDN has another useful TTFB test that lets you easily test your site's TTFB from ten different servers all around the world. This test is useful if you target a global audience as it lets you see how your server response time varies around the globe.

Just enter the URL to your site and click Test to view results for all ten locations:

KeyCDN TTFB test results screen

Again, you'll want to focus specifically on the server response times for the areas where you target. In the example above, you can see that our London server response time is the fastest on the list, which makes sense because we primarily target a UK audience.

Google Analytics

If you use Google Analytics on your website, you can also see real server response time data for your site's existing visitors. You can access this report by going to Behaviour → Site Speed → Overview. Look for the Avg. Server Response Time (sec) box:

Google Analytics site speed overview screen

In this example, .42 seconds means your average server response time for real visitors from all geographic areas would be 420 ms.

How to Reduce Server Response Time and TTFB

To finish things out, let's go over some tips to reduce server response time if you're seeing slow load times in the testing tools above.

Use Faster Web Hosting

You can try the other tips on this list first...but one of the best ways to reduce your server response time is to move to faster, more performance-optimised hosting.

After all, your hosting is what controls the "server" in "server response time", so your efforts to improve server response time will always be limited by the performance of your underlying hosting.

If you're hosting at Krystal, we use technologies like LiteSpeed Web Server and LiteSpeed Cache to offer speedy server response times and maximum overall performance, so you're set up for success.

If you're not hosting at Krystal, we'll help you migrate your sites over for free! Check out our shared hosting plans or our managed WordPress hosting to get started.

Use Page Caching

Page caching is another great way to improve server response time, especially for WordPress sites.

Here's how things work without page caching:

When someone visits your site, your server needs to process PHP and query your site's database for the content to display before it can respond to the request with the HTML for the page. This takes some time, which leads to a slower server response time.

With page caching, you can store the finished HTML output of that PHP processing and database querying in a "cache". Then, your server can respond to requests with the cached version, which takes less time and leads to lower server response times.

If you're hosting at Krystal, you can easily set up page caching using the free LiteSpeed Cache plugin.

If you're not hosting at Krystal (or another host that offers LiteSpeed Web Server), you can find other free caching plugins such as WP Super Cache or Cache Enabler.

Choose a Server Location That's Close to Your Visitors (or Use a CDN)

As we showed you in the server response time test examples from above, physical distance plays a big role in server response time.

For that reason, you want to make sure that your server's data center is as close as possible to your target audience. For example, if you're primarily targeting people in the UK, you'll want to choose a host like Krystal that offers UK-based web hosting.

If you have a global audience, you can also consider using a content delivery network (CDN) like the Krystal CDN to ensure lower server response time for all visitors.

For even better results, you can use a plugin like WP Cloudflare Super Page Cache to fully cache your entire site on Cloudflare's huge global network (instead of just caching your site's static files). This leads to very low server response time all around the world, but it can be complicated to implement for dynamic WordPress sites so we only recommend considering this for simple static sites, such as a portfolio or brochure site.

Note - if you decide to use WP Cloudflare Super Page Cache, you should disable page caching via plugins like LiteSpeed Cache.

Use a Faster DNS Provider

Our final recommendation to speed up your server response time is to use a faster DNS provider.

If you're not sure what DNS is, it's basically like the phone book of the Internet. More specifically, it's what connects your domain name with the IP address of your hosting server.

When someone visits your site, their web browser first needs to use DNS to look up the actual IP address of your server. This has to happen before your server can even start responding.

You can use different DNS services to act as this "phone book" and some are faster than others.

For example, in the DNS performance benchmarks from DNSPerf, the difference between the fastest DNS provider and the slowest is ~110 ms, which would already take up more than half of the ~200 ms that Google recommends for server response time.

Cloudflare is free and offers one of the fastest DNS services. Even if you disable the proxy and CDN services in Cloudflare, you can still use the DNS for free. Or, you can consider a premium service such as DNS Made Easy.

Speed Up Server Response Time Today

To recap, server response time measures how long it takes your hosting server to respond to a request from a visitor's web browser.

As such, finding ways to reduce your server response time can speed up your site and improve performance.

To run a server response time test, you can analyse your site's time to first byte (TTFB) using tools such as WebPageTest, Geekflare, KeyCDN and others.

If your server response time takes longer than ~200 ms for your target geographic areas, you can reduce your site's server response time via the following strategies:

  • Choosing faster, more performance-optimised web hosting, like Krystal Hosting.
  • Implementing page caching via a plugin like LiteSpeed Cache.
  • Making sure your hosting data center is physically near your target audience. Or, using a CDN if you have a global audience.
  • Using a faster DNS provider.

Do you still have questions about server response time? Let us know in the comments section! If you want to find out more about the personalised help that our Onyx Managed WordPress customers receive, feel free to get in touch via Live Chat.

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