Male or Female? Your Browser's History Might Tell

Martin Brinkmann
Jul 28, 2008
Updated • Dec 25, 2012

A website should not be able to read the the history of websites that a visitor to the site has visited previously in the web browser. An ingenious CSS hack and some spicy Javascript is however enough to use a trial and error method to find out if a user has been to specific websites. The method takes into account that visited websites are displayed different in the browser which makes them identifiable by scripts

Some webmasters use this method to display the social bookmarking and news batches of websites that their visitors have been on which is very effective in gaining popularity on those websites.

Others came up with a script that is using this method to estimate if a visitor is male or female. The Javascript makes use of the Quantcast Top 10K websites and the male:female ratio that they provide plus a neat algorithm to compute the percentages for male and female likeliness.

Mine turned out 50/50 because I don't use the history at all. Good luck and let me know what the script thinks about your gender..

analyze browsing history

The same principle could possible be used to display targeted advertisements. Have been to a lot of parenting websites lately? How about parenting ads? Like sports? How about an ESPN subscription? It's a bit scary, don't you think?

Update: Some browser companies have added protection against these kind of information retrieval techniques. You will receive a 50/50 ratio in those browsers as well if you run the browsing history analyzer on them. Mozilla, makers of the Firefox web browser have closed the leak in 2010 for instance so that all Firefox versions from that point in time on do not reveal information about previously visited websites anymore, at least not in situations where CSS is used to find out about that.


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  1. JoeSurfer said on July 30, 2008 at 1:18 am

    I had 100% of being female… news to me seeing as I’m a guy. The method might be cool but perhaps there’s some assumptions made on how ‘male’ or ‘female’ a site is?

  2. Rarst said on July 28, 2008 at 9:09 pm

    96% Male

    Too much software portals… :) And the method is seriously cool and clever.

  3. Thinker said on July 28, 2008 at 6:59 pm

    Likelihood of you being FEMALE is 2%
    Likelihood of you being MALE is 98%
    Hehe :D Mine top male sites:
    Site Male-Female Ratio 2.13 2.23 ^^

  4. Jonathan said on July 28, 2008 at 5:22 pm

    Likelihood of you being FEMALE is 54%
    Likelihood of you being MALE is 46%
    Odd… :)

  5. kazounet said on July 28, 2008 at 4:54 pm

    50/50 for me too, though I have a concequent firefox history :/

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