Last Updated on April 17, 2020
In the first post of this series, I talked about the page speed metrics that I think make the most sense to focus on, Time to First Byte (TTFB) and First Contentful Paint (FCP). There are a lot of different tools that can help us diagnose the issues that commonly cause problems with these metrics. Luckily for SMBs, there is no shortage of tools for helping get to the bottom of page speed issues
Testing Time To First Byte
Google PageSpeed Insights documentation recommends under 200ms for server response time. When testing TTFB, it’s important to remember that every tool will give different results, so remember which tool you use when you establish your baseline. Personally I like to run the same test on multiple tools to get a bigger picture of what is going on.
WebPageTest is a really helpful tool in diagnosing page speed issues, especially TTFB. One of the benefits of WebPageTest is that each test is the average of three tests, which I personally like.
Another helpful feature of the tool is the ability to choose a testing location, device, and connection type. As seen from the test below the TTFB was measured at 1700ms and is therefore in need of some definite page speed improvements.
One possible solution for this issue would be to enable the use of a CDN (Content Delivery Network) like Cloudflare to help these resources load faster.
“While a good TTFB doesn’t necessarily mean you will have a fast website, a bad TTFB almost certainly guarantees a slow one.” Harry Rogers
GTmetrix is another free tool that can be a bit easier to understand than WebPageTest. Signing up for an account gives me detailed information and allows for monitoring capabilities. It will easily show you the TTFB metric.
However, you need to look for “wait time” instead of load time when using GTmetrix. It’s also important to remember that this test is running on a single URL, so you are just getting TTFB for that particular page. If other pages on your site have more resources, you should run tests on multiple URLs.
Google’s PageSpeed Insights tool can be helpful for getting a quick snapshot of PageSpeed and what the recommendations are for improvement. It’s really easy to get hung up on trying to get a 100/100 in PageSpeed Insights but it’s important to remember that even the fastest sites may not get a perfect score. PageSpeed Insights makes it very easy to test on mobile or desktop.
Google PageSpeed Insights shows Field Data and Lab Data when scoring a site. The Field Data compares the site being tested with other sites in the Chrome User Experience Report for the last 30 days.
Lab Data is calculated under fixed conditions, using actual load speeds collected over time. My recommendation is to use both sets of data to get an idea of the loading times for the website being tested, which are more important than the PageSpeed score above.
Page Speed Insights Recommendations
The recommendations that come from PageSpeed Insights can be really valuable if you’re feeling overwhelmed by how to improve your page speed.
Referencing Estimated Savings can be really helpful if you’re trying to convince a client that they need to improve their page speed. Knowing exactly what images are causing the page to load slowly makes it a lot easier to correct that issue.
The TTFB recommendations are less in-depth in PageSpeed Insights but are still helpful if you’re wanting to know if it’s an issue. For a more in-depth look at what issues to fix for TTFB, our third post in this series, next week, will include a checklist.
The other tool that I like to use for testing page speed is ScreamingFrog with the Google PageSpeed Insights API connected. The benefit of using ScreamingFrog is the ability to test as many URLs as you want at once.
ScreamingFrog is free, up to 500 URLs. The API takes some setup but isn’t too hard. Having the ability to test all URLs at once can be really beneficial in getting the full picture when it comes to solving speed issues with a website.
Which Tool to Use
When you’re trying to decide what tool to use to test for page speed, it really comes down to personal preference and the level of knowledge you have. If you’re just starting out with SEO or are just trying to diagnose why your website might be slow, I would recommend starting with Google PageSpeed Insights. If you have a bit more technical knowledge or want to dive deeper, WebPageTest is great.
Make sure to come back next week for the final post in this series, where we dive into how to improve your page speed, complete with some checklists to help you get going.