- Testing Time to First Byte (TTFB)
- Analyzing total load times, page sizes, and # of requests
- Checking performance from different geographical locations
- Checking minification of your scripts
- Finding large images resulting in bottlenecks
- Measuring performance of your Content Delivery Network
- Verifying that assets are loading correctly from your CDN
It is also important to realize when running tools like these that a 1st time DNS lookup will usually be slower. If you are comparing total load times it is sometimes better to run tests multiple times and take an average of the results.
Here are the top 7 free tools you can use to optimize the speed of your website:
WebPageTest is great too but it has one distinctive advantage - it has over 40 locations to choose from and over 25 browsers (including mobile). If you click on “Page Speed” after running a test you’ll find an overall grade as well as a checklist of some suggested changes (in order of importance) for increasing your website’s speed. It assigns you a grade from F to A based on different performance tests. It’s report is divided into six sections which include a summary, details, performance review, content breakdown, and screenshots. One cool feature of WebPagetest is the ability to select the country from which to run your test. This can be used to track how your speeds vary across the world.
Link to tool: WebPageTest
Pingdom is a great free tool that offers great analytics. Their reports are divided into four different sections which include a waterfall breakdown, performance grade, page analysis, and history. Pingdom lets you examine all parts of your web page (file sizes, load times, and other details about every single element of a web page), share your results and trace your performance history. Every time you test your web page on Pingdom, the results are saved and you can review them later and also see how things change over time.
Link to tool: Pingdom
3. Google PageSpeed Insights
Google PageSpeed Insights grades your website on a scale of 1 – 100. The higher the number the better optimized your site is. Anything above an 85 indicates that your website is performing well. PageSpeed gives you reports for both the desktop and mobile versions of your site. It also recommends what improvements you should make next.
Link to tool: Google PageSpeed Insights
GTmetrix goes into great detail as it checks both Page Speed and YSlow metrics, assigning your site a grade from F to A. It’s reports are divided into five different sections including PageSpeed, YSlow, waterfall breakdown, video, and history. It's free to register and you can test your web from 7 different geographical locations. Video playbacks are available - they help you analyze where your bottleneck is occurring. And you can run Adblock plus on it to see how much ads affect your loading.
Link to tool: GTmetrix
5. Website Test
WebsiteTest from Yottaa lets you test your website speed from multiple locations around the globe using real browsers and consumer connection speeds. Enter multiple URLs to compare them side-by-side, or compare sites against industry pages. Perform advanced testing, including multi-step transactions, video capture, content blocking and more. It’s extremely simple to use and the results are easy to read. Simply said, it’s a great free tool that’s easy to master and gets the job done.
DareBoost allows a stunning number of over 100 different checkpoints when analyzing your site for speed. It gives you a score of 1 – 100. You can test on desktop vs mobile, Firefox vs Chrome, and five different locations. There's a free account and a paid version that gives you much more services. The reports are great too, they show you how good is your SEO, the code quality and how accessible is your site.
Link to tool: DareBoost
7. Google Chrome DevTools
Another great free tool from Google. It's extremely simple to use and you can launch it anytime in your Chrome browser. They've recently added an aggregated details panel into the waterfall timeline. This allows you to more easily see what is costing you the most time, and you can then break it down by domains, sub-domains, etc. We recommend this for beginners because it's so easy to use and it gets the job done.
Link to tool: Google Chrome DevTools
This goes one more time - testing your mobile is crucial. Since mobile is taking over, optimizing your mobile web into a fast and responsive website is a key factor. Another way to simulate a speed test on a mobile device is to use Chrome developer tools in device mode. To enter device mode click on the small phone icon in Chrome DevTools or you can press Ctrl + Shift + M (Cmd + Shift + M). You can then choose what device you want to emulate, the orientation, and even resolution. You can also change the network throttling to see how your website actually would render on say a regular 2G or 4G connection.
This little insight helps you see how well your mobile web does in bad connection conditions. Getting an A on this test will surely reduce the bounce rate a lot. Web speed and optimal mobile browsing experience are everything these days - don’t wait too long to optimize too late.