Which tool are you using to analyze your website's speed?

Which tool are you using to analyze your website's speed?

As we all already know, website speed is highly important for any modern SEO.
Google takes into consideration how much times your website takes to fully load for the average user and makes all this a ranking factor for SERPs.

For a long time I used Google's own speed test: https://developers.google.com/speed/pagespeed/insights/
But I found its hugely unreliable and often doesn't indicates the real values and real problems a website speed's may have.

This is why my main speed tester is GTmetrix at https://gtmetrix.com/ - analyzes pretty much everything you need to know. But as a SEO I usually look only for PageSpeed Score, YSlow score, Page load time, Total page size and number of Request.

If I consider a website is too slow I move the recommendations given GTmetrix to a programmer so he can optimizes the code or everything else that needs improvements.

Here are the stats on one of my wesbsites:


What speed tester are you using? to measure our website's speed?