Lighthouse: Reduce initial server response time

Overview

Time to First Byte (TTFB) measures server response time before content begins loading on your page.

Improving TTFB speeds up page loads and enhances overall performance.

How does server response time affect page performance?

When a user requests your page, this request needs to be sent to the server, and the server needs to generate an appropriate response and send back your page resources.

This entire process depends on multiple factors such as network transfer speeds, latency, efficiency of the application code, and performance of the server.

Put simply, if any of these elements are slow, your TTFB is affected.

A slow TTFB significantly impacts your website performance; your visitors will see a blank screen while waiting for your server to respond with the first byte.

This may even result in your visitors getting frustrated and leaving your page altogether.

A fast TTFB, however, means your visitor receives a rapid response when they initiate their request. The faster the first byte arrives, the sooner the rest of your page resources can be processed.

Note that there are many definitions for TTFB; GTmetrix considers TTFB to be the sum of the Redirect Duration, Connection Duration, and Backend Duration.

While this audit, in particular, looks at the initial server response time (i.e., Backend Duration), it does contribute heavily to your TTFB and you should aim to optimize TTFB in general.

How does GTmetrix trigger this audit?

This audit will be triggered if the initial server response time exceeds 600 ms.

How to reduce server response times?

There are multiple strategies to improve your server response times. Some of the key ones are:

1) Optimizing your application code (including database queries)

The Application code is crucial to web performance optimization.

We strongly recommend that you solicit developer assistance as you are now dealing with the core logic of your website.

When you engage in code profiling, some of the optimizations include:

• Streamlining the codebase, making functions more efficient
• Reducing complex operations or bundling up code to be only executed when needed
• Making database queries more efficient, removing unnecessary queries

To learn more on optimizing application code, read our Why is my page slow? article.

2) Implementing server-side caching

Caching is the practice of serving a pre-generated version of your page when requested, rather than having the server process and generate the page on demand.

There are many caching solutions out there at the server-level. Your host may already engage in server-side caching, so be sure to reach out to them to clarify.

Using a Content Delivery Network (CDN)

A CDN stores cached versions of your site’s content on servers distributed around the world. When a user visits your site, content is served from the CDN server closest to them instead of your origin server.

This reduces latency and can significantly improve initial server response time, especially for visitors far from your primary server location.

Popular CDN providers like Cloudflare and RocketCDN can be enabled with minimal configuration and often integrate directly with hosting platforms and CMS caching plugins.

Learn more about CDNs in our Basic Guide to CDNs article.

For WordPress (or other CMS) Users

WordPress (or other CMS) users can implement page caching through caching plugins.

For example, installing a caching plugin like WP Rocket can help reduce your TTFB instantly out of the box while easily integrating with RocketCDN or other third-party CDN providers.

Read our detailed WordPress optimization using WP Rocket guide.

3) Upgrading server hardware for more CPU or memory resources

If your budget allows, talk to your hosting provider or a developer to analyze resource usage and determine if you can upgrade the origin server's hardware specifications.

Note: This is a bit of a band-aid solution - if your application code is woefully inefficient, all the hardware resources in the world won't reduce load times.

In summary, assess your situation and weigh out the pros and cons before committing to a solution.

For example, consider upgrading from your low-cost hosting plan if you have a complex WordPress website.