

How does Google Analytics measure site speed?  - yahelc
http://stackoverflow.com/q/6166074/172322

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blauwbilgorgel
Since the announcement of the Page Speed Toolbar I predicted Google would not
simple crawl a website, it would render it.

Now we have previews in the search results, so we know for sure that Google
renders websites.

Next to detecting hidden spam or javascript layout changes, I presume this
rendering can be used to produce a waterfall of the site loading process.

So while Google does this with a HTML5 feature in modern browsers, internally
it should already have:

\- page speed scores

\- render scores (perhaps render time)

of all websites in index, regardless the browser their users use.

That is how I think Google measures site speed; it uses these known non-HTML5
factors for ranking the fastest websites.

~~~
dave1010uk
This is very likely how Google measures site speed for ranking, as well as
anonymous submissions from the Google Toolbar. Google Analytics also lets you
filter this data by other metrics such as browser and geographic location.

As for the W3C timing spec, it looks like Firefox is planning on implementing
this too: <https://bugzilla.mozilla.org/show_bug.cgi?id=570341>

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n_are_q
I really wish GA tracked all the metrics exposed by the timing spec, instead
of combining them into one overall value. It's great that this reports numbers
from actual users' machines instead of a headless render process on a
monitoring server somewhere though. Here is hoping FF implements support for
this soon.

