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Seems like vBulletin 3 does user agent sniffing...

Posted January 22nd, 2012 at 8:50 PM by Twiggy
Updated January 22nd, 2012 at 9:14 PM by Twiggy

...and serve up different content to users of Internet Explorer. Invalid content for Internet Explorer 8 and newer.

I went into this forum and also Victory Road as usual, but I was having fun messing around with my user agent string. Probably to test how sites react to my spoofed user agent string...


This is how Victory Road, a vBulletin 3 forum, looks before I changed the user agent string. Notice the Last Post info box - the last two lines became one line. This is not the expected behaviour - Firefox, Chrome and Opera show all three lines. It's caused by the vBulletin software serving up code that's right for Internet Explorer 7 and older, not knowing that Internet Explorer 8 and newer doesn't have an issue with that... and break it instead.


This is the same thing in PokéCommunity. (If you were wondering how I got box-shadow to work in Snivy's Holiday, well, I intercepted the request to the original CSS and instead made it load my copy of the same style's CSS, with the unprefixed box-shadow inserted. Fiddler2 can be a powerful tool to debug pages.)


And let's see what happens when I change my user agent string to one of Firefox 9...


That's a big difference! There is a good reason why user agent sniffing and serving different content by it is not a good idea. Browsers can and will get bugs fixed - never assume that it'll never change!

This MSDN blog post, "The Perils of User-Agent Sniffing, 2011 Edition" should help a lot in understanding the issue.
Posted inMisc, ‎PokéCommunity stuff
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Total Comments 4


  1. Old Comment
    Ulterior motives for advertising forums how dare you hope your ass is banned NOW!!!!!
    Posted January 23rd, 2012 at 2:39 PM by
  2. Old Comment
    Oryx's Avatar
    Originally Posted by Patchisou Yutohru View Comment
    Ulterior motives for advertising forums how dare you hope your ass is banned NOW!!!!!
    Minimodding, infraction!!!!!111!!!!11
    Posted January 23rd, 2012 at 5:03 PM by Oryx Oryx is offline
  3. Old Comment
    Posted January 26th, 2012 at 2:07 PM by
  4. Old Comment
    Forever's Avatar
    she'll unleash jake onto the world imo.
    Posted January 26th, 2012 at 9:39 PM by Forever Forever is offline

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