View source for Utma, utmb, utmz cookies



The [[cookies]] named {{inlinecode|__utma}} through {{inlinecode|__utmz}} are stored by websites that choose to use [http://www.google.com/analytics/ Google Analytics] to see how people use their websites.


These cookies support the part of analytics that actually take some amount of remembering to figure out
{{comment|(the analytics also sends in some other things that can be figured out on the spot, such as screen resolution)}}.


Some details:
* '''<tt>__utmz</tt>''' records ''whether'' the visitor came from...
:: a search engine (and if so, the search keyword used),
:: a link, or 
:: from no previous page - as is the case when you use a bookmark, or typed in a URL themselves

* '''<tt>__utma</tt>''' stores 
:: the amount of your visits
:: the time of the first visit, the previous visit, and the current visit <!-- (presumably partly for double checking of this information)-->


* '''<tt>__utmb</tt>''' and '''<tt>__utmc</tt>''' are used to ''approximate'' how fast people leave, by recording when a visit starts, and approximately ends.
:: If you look at cookie state changes {{comment|(e.g. using {{search|firecookie}})}}, you will see these change regularly and __utmc expire quickly.<!--
:: __utmc is no longer necessary in later versions like ga.js?[https://developers.google.com/analytics/devguides/collection/analyticsjs/cookie-usage#gajs] -->


Also:
* '''<tt>__utmv</tt>''' is used for user-custom variables [https://developers.google.com/analytics/devguides/collection/gajs/methods/gaJSApiBasicConfiguration#_gat.GA_Tracker_._setCustomVar]
<!--
* '''<tt>__utmd</tt>''' - how you arrive? helps tracking paths through the site?{{verify}}
-->

* '''<tt>__utmx</tt>''' is used by [http://www.google.com/websiteoptimizer Website Optimizer], when it is being used{{verify}}

* '''<tt>__utmt</tt>''' is "used to throttle request rate"[https://developers.google.com/analytics/devguides/collection/analyticsjs/cookie-usage#gajs]
* '''<tt>__utmk</tt>''' seem [[digest hashes]] of utm values {{verify}}




These cookie names seem to come from an earlier versions of google analytics called [http://www.google-analytics.com/urchin.js urchin.js], '''U'''rchin '''T'''racking '''M'''odule.

The names are still used by the newer [http://www.google-analytics.com/ga.js ga.js].

It seems that similar lettering, without the utm, was used by [https://www.google-analytics.com/analytics.js analytics.js] (Universal Analytics).

<!--
GA4's gtag/js 
-->


===What about the analytics they are part of?===


The mentioned cookies support things that rely on some sort of memory.
: how you got there (search, link, or bookmark) 
: how often you visit
: how long you stay


To get some idea of '''what else''' is sent in (mostly things that can be figured on the spot), 
you can e.g. use your browser's debug console to look at the request made.

For ga.js, the request to google (to __utm.gif) includes things like  
: <tt>utmcc</tt> - contains the __utma through __utmz cookies
: <tt>utmht</tt> - timestamp

: <tt>utmhn</tt> - hostname that you are visiting
: <tt>utmp </tt> - path on site
: <tt>utmdt</tt> - document title<!--
: <tt>utmcs</tt> - page's character set, e.g. "UTF-8"-->

: <tt>utmul</tt> - user/browser(?) language, e.g. "en-us"

: <tt>utmsr</tt> - screen resolution, e.g. "1920x1080"
: <tt>utmsc</tt> - screen colors, e.g. "24-bit"
: <tt>utmje</tt> - java enabled, either "0" or "1"?
: <tt>utmfl</tt> - flash version, now often "-" as Flash has been retired

: <tt>utmac</tt> - the analytics account this is reported to

: <tt>utmwv</tt> - version (of tracking code)
: <tt>utmn </tt> - random number (to avoid missed reports due to cached requests?{{verify}})
{{comment|(these names happen to be named similarly, but are not cookies - they don't need to be)}}


Since this contains information about the visit, not so much and not about you, none of this seems particularly privacy-sensitive to reveal 
to the site owner, or to google.

Yet if you wish to block such ''reporting'' on principle, and get an active idea how common such invisible tracking is rather than just block them (ABP, Privacy Badger), look at things like [https://www.ghostery.com/ Ghostery], which shows you the list of used trackers, and which one it's been configured to block. <!--
(and is a little more aggressive than e.g. [https://adblockplus.org/ ABP] is by default)-->


[[Category:Internet]]