Confirmed: Google Site Speed Data Fed by Chrome Users

[robzilla]

Not much of a surprise, but always good to get official confirmation:

The short version is that Google is now using performance data aggregated from Chrome users who have opted in as a datapoint in the evaluation of site speed (and as a signal with regards to rankings).

[...]

John [Mueller] has confirmed this information in a Google Webmaster Central Hangout [15m30s, in German], where he explains they're using this data along with some other data sources (he doesn’t say which, though notes that it is in part because the data set does not cover all domains).

Google Confirms Chrome Usage Data Used to Measure Site Speed [moz.com]

[ergophobe]

To answer analis' question, though...

- Always use multiple tools for many reasons (different networks, different methods, different server locations).
- Understand what the tools are measuring.
- keep records of your results with a given set of tools so that you can compare later using the same tools.

On the last point, for example, GTMetrix changed the way they measure a year or two ago because they realized that with things like lazy loading images, you can't just measure how long it takes to load all the resources defined in the HTML document. Other tools use simpler models. So now they use a standard that is roughly the last request made before a two second gap without a request. That means that load times might seem higher on one tool than another.

Tools that I use
[gtmetrix.com...] (Page Speed Insights and Y Slow! in one report, plus other stuff)
[webpagetest.org...] (multiple test runs and lets you see the variation easily, but does not load as many resources as GTMetrix test)
[bytecheck.com...] (TTFB test - good for seeing how long DNS lookup and SSL negotiation takes)
[developers.google.com...] (How Google sees your site)
[testmysite.thinkwithgoogle.com...] (How Google sees your site)

And of course there are some good tools in Chrome itself now.

Plus some DNS checkers if need be. And dedicated single-factor checkers (gzip, etc).

But the above give you a decent picture of what is affecting load times (the first three) and how Google tools see it (the last two).