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Does Google execute JavaScript?

stephanboyer.com

1–10 of 114 posts

Re: Does Google execute JavaScript?

#2
Good, uncomplicated article.

If you can get Google servers to execute Javascript, that sounds like a possible attack vector. It's likely that Google runs these in a proprietary feature-sparse interpreter.

The lack of AJAX would make it difficult to leak information about the black-box interpreter.

Re: Does Google execute JavaScript?

#3
My pet theory is that part of the anonymous usage data Chrome sends back, is digested page contents that go into pagerank. And such browser level digesting would be on rendered pages (after JavaScript execution.)

I have no other reason to believe it is true other than it's what I would do to distribute the job of crawling the web to my users if i were Google :-)

Re: Does Google execute JavaScript?

#7

Nicely done! I have been writing crawlers for a while now and executing Javascript is very expensive and slow, even for Google. When I crawl the web I usually run javascript from a headless browser only on top priority sites.

What I find very useful is to run Firefox through Selenium with a plugin installed to disable pictures. Then it's blazing fast.

Re: Does Google execute JavaScript?

#8
post #3

My pet theory is that part of the anonymous usage data Chrome sends back, is digested page contents that go into pagerank. And such browser level digesting would be on rendered pages (after JavaScript execution.) I have no other reason to believe it is true other than it's what I would do to distribute the job of crawling the web to my users if i were Google :-)

Yeah, it would make sense. There has to be more reason to giving people a free web browser other than just that it uses Google search.

Re: Does Google execute JavaScript?

#9
My pet theory is that Google actually developed chrome as a web crawler and that consumer release was to ensure that Google would always be able to crawl pages (since sites would always want to work properly with chrome)

It also explains why they effectively killed flash and Java applets. They were competing technologies that weren't owned by Google and not crawlable. If they would have taken off, Google's position as top search engine could have been in danger

Re: Does Google execute JavaScript?

#10
I've checked a site I know which is using nothing but Angular/JS on the frontend towards PageSpeed Insights [1] and it fully failed that test - no results visible. Also, the whole page is not indexed but the root URL itself. No page snippet preview, nothing.

[1] https://developers.google.com/speed/pagespeed/insights/

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