Time to First Byte (TTFB)

When we measure our site performance and usability, we don’t always consider Time to First Byte – but we should.

TTFB can tell you a lot about your server speed and site health, and help you identify where you need to optimize for performance.

In fact, it’s so important that Google has tweeted about its relevance to page ranking and SEO.

Which is why understanding exactly how it works is so crucial. Being able to read and analyze your TTFB allows you to build a better strategy for site speed optimization.

Let’s break down what it is, what affects it, and how to speed it up.

What is TTFB?

TTFB (Time To First Byte) is the measurement used to indicate how long it takes for a browser to receive the first byte of data from a web server.

It’s used as a benchmark in measuring a well-configured server application. The smaller the TTFB, the better the application.

TTFB is made up of roughly four steps:

Step 1: A request is sent to the DNS server to connect the URL to the correct IP address, and then the DNS server sends back a response.

Step 2:  The client then sends a SYN request to the server via a TCP handshake, and the server responds with a SYN/ACK message.

Step 3: An SSL handshake is used to confirm that the connection is made securely.

Step 4: The last step is waiting for the web server to generate the content and send it to the client, and, once the first byte is received, TTFB is successfully logged.

A common misconception is that it’s calculated after DNS lookup times – but the DNS request and response are still included in TTFB.

(It also shouldn’t be confused with load time,  which is how long it takes for the entire web page to load, including image load. TTFB is literally just the first byte of the main html page.)

Why does TTFB matter?

TTFB is key to how both visitors and Google interact with your site, and directly impacts:

• User experience

TTFB helps reduce bounce rate and improves user browsing experiences because the web response is faster.

It’s also a good indicator of your site-wide efficiency and can help you pinpoint other issues that can impact UX.

• SEO and Rankings

TTFB is a major factor in your search engine rankings.

SEO rankings aren’t just based on content – they’re also based on UX, load times, and site speed. TTFB can contribute to other metrics like TTI (time to live), which in turn impacts your rankings.

A good SEO strategy is still important, but having a high bounce rate due to slow TTFB can cancel out all your hard work.

How do you know if your TTFB is slow?

For TTFB metrics, anything above 500 ms – 1 s is considered slow – not emergency slow, but slow enough to need solutions.

There are a couple of great tools out there for checking your TTFB:

• Ahref’s When using it to analyze your site, you can find information about TTFB under the performance section.

(It can, however, give you different readings each time, so you should cross-check your TTFB with other sources)

• WebPageTestWith a web page test, you can just input your URL and check the data to see your TTFB.

  When we tried it with Google’s homepage, their TTFB was only 235ms (which is optimal)  

• Lighthouse web development You can use their tool to analyze your site (you’ll find the TTFB under the opportunities section (You can also access lighthouse directly through Google Chrome)

• Directly through Google Chrome You can check your TTFB by inputting your URL into chrome, selecting the three vertical dots in the toolbar, and going to tools/developer tools/ right-clicking an element and checking the timing tab:

How do you measure TTFB accurately?

You can check TTFB using cURL from your unix terminal app using the following command:

curl -s -o /dev/null -w "Connect: %{time_connect} TTFB: %{time_starttransfer} Total time: %{time_total} \n" "https://www.mindspun.com"

What causes slow server response time?

There are a lot of things that can cause a slow server response time – constrained resources, small server size, database size, or network and memory.

(You should check load density to cover your bases, but it’s unlikely to be the issue)

To identify the main issues, you should check memory, network and databases looking for periods of 100% utilization (If there’re a lot of fluctuations throughout the day it’s likely the issue is load)

Other common reasons why you have slower than normal TTFB can include:

• Dynamic content creation
• Networking issues
• Issues with server capacity
• Database design or configuration
• A poor web server configuration

Your application could also be the problem. WordPress and other Content Management Systems (CMS) are the worst for this  because there’s a lot of work that goes into building the page before it can be sent back to the user.

Modern CMS are better but you still need to build the page for each request and which is slower than serving a static page.

How do you fix slow server response time?

This depends on your application and server but there are a few things you can try:

• Performance tune your applicationThis could include upgrading your server’s hardware for more memory or CPU, or optimizing your server’s application logic and queries database for faster systems and pages.
• Get rid of anything unnecessary Remove any plugins, scripts, or extensions that aren’t serving any real purpose.
• Change your service provider Select a provider that’s optimized for your server and application needs.
• Keep up to date with logs Monitor logs to track any indications that a system is being overloaded.
• Keep software updated Make sure to update your server stack, website, plugins or extensions to improve performance and reduce load times.
• Implement a caching mechanism A caching mechanism can help minimize the caching issues (like keeping stored versions of pre-built pages)

  That’s why we’ve created the Mindspun Hosting, which caches pages automatically to give you the same performance as a static site.

  It also serves pages from a cache close to a user to minimize the time it takes for bytes to cross a network.

TTFB is often overlooked, but it’s a crucial aspect of web performance and user experience.

Make sure you’re monitoring your TFFB, keeping all your software up to date, and investing in tools that’ll help you rank better and improve your site’s performance.