Randomized Google search parameter 'hs' - what's it used for?

[Receptional Andy]

Today I noticed an additional parameter being used in my Google search URLs, originating from a hidden text field with the name 'hs'.

This field changes on each pageload, and consists of three random characters - a letter or a number, e.g. pCv or 4yu.

I'm aware of the usage of most of the Google search parameters, but I've never seen this one before.

A typical URL for me would be www.google.com/search?hl=en&client=firefox-a&rls=org.mozilla%3Aen-GB%3Aofficial&hs=pcV&q=widget&btnG=Search

hl - interface language
client and rls - supplied by software manufacturers to track usage
q - the keyword
btnG - I hit the search button
hs?

Seemingly, this variable appears for any search where the parameter 'client' is set to 'firefox' (plus any other characters) appears (e.g. &client=firefoxasdas will trigger it). I couldn't find any other parameters or values that had the same effect (e.g. sourceid=opera and other tracking-type info).

Does anyone have any idea what this might be used for?

[tedster]

Interesting find, Andy. I haven't been able to pin this one down yet - mostly because it is so hard to duplicate. I only managed to get one page so far (using Firefox) that included the parameter 'hs=' in the links.

Hoping these observations help -

1. the page used two different 3-letter values for the paramater

2. 12 of the occurances used one value as part of the rgular Google interface (links for Images, News, Advanced Search, etc)

3. The other value for the 'hs' parameter appeared 26 times on the page: in the ten "1, 2, 3... Next" links at the bottom and in sixteen "similar pages" and "cached" links.

I've tried to generate a second example by turning off cookies, turning off the cache, using the toolbar for the search, using the "Google Search" button and using "Enter" on the keyboard. So far I can't generate a second instance to study. But I did see it once, on the first try.

Not sure this means anything, but I noticed that the 'hs' parameter did NOT appear in the status bar when I hovered over those links, even though other parameters in the url, such as 'hl', did. Seems like some javascript is changing the status bar display.

[leeds1]

I just all of this with a query - I was not signed in at all. IE7.0

www.google.co.uk/search?hl=en&q=querystring&revid=669207783&sa=X&oi=revisions_inline&resnum=0&ct=broad-revision&cd=2

This was from one of the "related" items

I guess that doesn't matter so much ?

[Receptional Andy]

I can get this variable to appear consistently with any search using the &client=firefox(+any characters) parameter so I think it may be related to firefox usage. It then appears in nex/forward links, although not elsewhere that I've seen. I can get this to appear with other browsers as long as I include this parameter.

For reference, an easy way to check what variables Google is setting for a search is to use a developer toolbar of some description within your browser. So, in firefox with web developer extensions installed choose Forms >> Display Form Details.

The search below causes the variable to be set for me:

[google.com...]

Tested in Opera/firefox/IE on a couple of different connections.

I'm sure it's nothing important, but I'm just curious as I can't see much value in the random data unless it's some kind of verification, perhaps. I've got a list of variables set for searches somewhere which I should try to keep up to date!

[edited by: Receptional_Andy at 6:24 pm (utc) on May 11, 2008]

[tedster]

Thanks for the extra detail. Yes, i can confirm your observation. but it is a .little bit different than what I first saw. There's only one 'hs=' value assigned for the entire page, and it does show in the status bar.

Ah, the Google mysteries!

[Tastatura]

my $0.02 - this is what I did and observed:

-using FF I typed widgets in SE search bar (that thing all the way left and top)
-this is what url bar showed (no hs param.):
http://www.google.com/search?q=widgets&start=0&ie=utf-8&oe=utf-8&client=firefox-a&rls=org.mozilla:en-US:official

-if I hover over over links to additional serp pages (gooogle 1 2 4 ....) I see this - with parameter hs=REw in urls for all additional serp pages:
http://www.google.com/search?q=widgets&hl=en&client=firefox-a&rls=org.mozilla:en-US:official&hs=REw&start=10&sa=N

-after I click on any additional serp links hs parameter changes, in this case hs=X1G, for all of them, and I see something like:
http://www.google.com/search?q=widgets&hl=en&client=firefox-a&rls=org.mozilla:en-US:official&hs=X1G&start=40&sa=N

If I go to G's main page and type in search query hs parameter is non existent in url (including hovering over links to additional pages)

[edited by: tedster at 8:37 pm (utc) on May 12, 2008]
[edit reason] turn off graphic smile faces [/edit]