I spend a lot of time testing people’s websites. It’s become something of an obsession, after learning why my own website was running slow, I learned more about more about server response times. And I’m still learning.
People used to like to say that if your website loaded in under 2 seconds, you had nothing to worry about. That may well have been true two years ago. But now? Sorry, but nowadays if you’re measuring your load time on something like GTmetrix, then I’d want to see my website loading in under 500ms (milliseconds) i.e. half a second (1000ms being a whole second). Why? Well, that’s because GTmetrix is testing the load speed of the desktop version of your website over an unthrottled connection. That’s equivalent to how most of us view the internet, at home and in the office. But what Google is interested in, for its speed testing, which it plans on taking a lot more notice of in May 2021, is how fast your website loads over a 3G Fast connection. And it is testing that load speed on a simulated Moto G4 mobile phone.
Therefore, based on the half a second rule. Every millisecond counts. What are you going to do with those precious 500ms?
If your web server has a TTFB of less than 50ms. That means that 10% of your total loading time is taken up simply to wave hello to the server and deliver the first tiny byte of data. That’s before any real content loads. It matters not how many images you have on your website, nothing has loaded at this point. It’s merely saying hello to the server and sending back the 1st byte of data. Hence “Time to First Byte”.
What if your server has a TTFB of 100ms. Then you’ve already used up 20% of the total load time you are trying to achieve.
A TTFB of 250ms. Well, that’s 50% of the total you are trying to achieve. You’d better be loading a really small, light website if your server takes 250ms simply to send the first byte.
As hopefully you can see. If your server is taking up too large a part of your loading time, then it really isn’t great. You will already be working against the tide – an uphill struggle to get your website fast enough to please the Core Web Vitals test.
How do I test my servers TTFB?
Easy. Just put your URL into this testing site. You are looking for a figure of 50ms or less for your London server. You can also see how fast the server performs in other countries too. The San Francisco server for instance will most likely effect your results in Google’s Page Speed Insights test, as that is most likely where Google is testing your site from, not the UK.
You can also run your URL through GTmetrix, however I find their results don’t always match those showing in KeyCDN Tools – and I trust that test more.
In GTMetrix, make sure you change the settings to be your nearest city (London for us UK folk) and the connection is unthrottled. Also make sure you are testing the correct URL, with the correct format, with or without www and it should probably be https:// at the start.
It’s shown in various tabs in the GTmetrix interface, but the first place you can see it is on the main screen, as shown by the red arrow below. Run the test a few times, the results will vary slightly over time. But they should average out at around the same figure. If it’s really bad, then guess what – you have a slow web host most likely and perhaps you should consider changing providers.
Have a read through my other articles on website speed factors and how to speed up your website. I also run a short 2-3 hour course on the subject for those that are interested in learning more.