We are currently redesigning our website. The company we've hired to do the redesign is advocating the use of jQuery to render the pages dynamically. Our SEO specialist is under the impression that many larger corporations may have jQuery blocked in their proxies to prevent their users from visiting sites like Facebook.

Is this something you are aware of?

Forgive me if this is off topic for SF.SE!

  • 2
    Haven't heard of jQuery being blocked across the board. jQuery is pretty much everywhere now. The developers that don't use jQuery are those that handcraft their own industrial strength javascript using something like Aptana.
    – Greg Askew
    Sep 7, 2012 at 20:26
  • Why would an SEO guy know what was going on in corporate networks? They are two unrelated fields... Sep 8, 2012 at 0:58
  • Might, maybe be appropriate for the webmasters Stack Exchange site, but I don't know if they'd know either. It's not like there's one standard among large corporations for what's blocked at the firewall, and I suspect @MichaelHampton 's answer might be as good an answer as you're going to get. It just depends on what $corporation decides to do with its network. There's just not a lot of standardization or standards at the level of detail wrt to firewall policy that you're talking about. Sep 11, 2012 at 23:28
  • FWIW, Facebook doesn't use jQuery. Why doesn't facebook use jQuery?
    – MrWhite
    Sep 4, 2015 at 10:03

2 Answers 2


Typical Web filtering appliances/services classify web sites into categories, and then each category is permitted or blocked based on corporate policy. Some, such as Barracuda, use a reputation based system. They almost always also allow for local exceptions.

So, if you host the jQuery code on your own site, it will be permitted or blocked the same as the rest of your site would be.

If you use a hosted solution such as jquery.com or Google APIs, then it will be permitted or blocked based on the classification for that domain.

If you want to be 100% sure that your code would get through to sites that would normally permit your web site to be viewed, host all of the JavaScript within domains under your control.

  • alot of companies selectivy block sites or dont trust them till they have been categorised/allowed. some targeted blocking may be done for things like the google cache as it is "website anonamizer" etc. if you host the code its most likely to be allowed after the site is catigorised by a user.
    – Kendrick
    Sep 7, 2012 at 21:49

You can avoid this incluiding the libraries at your server, then you will solve the problem. If you link jquery from the jquery repository of google code might cause you problems

  • How would linking to ajax.googleapis.com cause problems? It's hugely popular. Anyone blocking it would make a good chunk of the web nonfunctional. Sep 7, 2012 at 21:49
  • @GeraldCombs: the intent of those filters is precisely to "make a good chunk of the web nonfunctional" Of course, the trick is to make that chunk match with the not-for-work chunk
    – Javier
    Sep 7, 2012 at 22:35
  • it could cause you problems on loading, Ive tested many sites and sometimes the loading time for the library could take more time when is from google code, also include the jquery at your server will give u the chance to know more especificly where and what to block
    – jpganz18
    Sep 7, 2012 at 22:51
  • "How would linking to ajax.googleapis.com cause problems? It's hugely popular." says someone who's never been to China and tried to use stackoverflow...
    – michael
    Dec 3, 2017 at 3:51

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