What do authuser=0, etc., mean in a Google URL? [closed]

Question

I noticed google.com has this at the end,

https://www.google.com/webhp?hl=en&tab=ww&authuser=0

It isn't a virus is it?

This was on chrome

I also noticed another similar to that on internet explorer

https://www.google.co.uk/webhp?hl=en&tab=ww

Answer 1

No, this is not a virus.

The authuser parameter is a way of controlling which Google account you're using (only useful if you have multiple accounts logged in).

From this blog post:

What’s controlling its choice? It turns out it’s the order you sign into the accounts. If you look closely at the URLs, either by mousing over the links in the account switcher or by looking at the URL you end up at for gmail but not for docs5, you’ll see an “authuser” or “u” parameter which is a low-valued integer. It starts at 0 for the first account you sign into, and counts up from there as you sign into additional accounts.

If you navigate directly to docs.google.com (or mail.google.com, etc), you’ll get the account currently associated as authuser 0, which is the first account you signed into.

I'm unsure what tab does, but hl changes the language (but not search localisation) - try changing hl=en to hl=de and see what happens (reference).