Recently a URL was posted on Ask Different that looked like this:

Why does it have the "?as=1" at the end of it? I understand that it is part of the workings of the website, but what is its purpose?

  • 1
    I assumed it was to indicate you came from the site drop-down (in the upper left).
    – Kevin
    Jan 31, 2012 at 22:41
  • @Kevin Ok, that's right, but what does that do? Just notify SE who's visited the site from the drop down menu?
    – daviesgeek
    Jan 31, 2012 at 22:42
  • 1
    Probably, for statistics - x% of new users on this site came from other sites via the dropdown, etc.
    – Kevin
    Jan 31, 2012 at 22:43

3 Answers 3


I've been exploring since yesterday in response to this comment and have found the following so far:

  • ?cb - A link from the community bulletin of a site.

  • ?newsletter - A link to a question from the emailed community newsletter. Also includes ?nlcode

  • ?rq - A link to a question from the related questions sidebar.

  • ?lq - A link to a question from the linked questions sidebar.

  • ?atw - A link from a site's automated Twitter feed.

  • ?stw - A link created by the share button posted automatically to Twitter.

  • ?sfb - A link created by the share button posted automatically to Facebook.

  • ?sem - A link created by the know someone who could answer this question box sent via email

  • ?blb - A link to a community blog/Stack Exchange blog from the footer on the main site.

  • ?noredirect - Stops a migrated question from automatically redirecting to its new location. Additionally, for logged-out users, stop an unanswered duplicate from redirecting to its target.

  • ?mnu - Appended to the links on the Welcome banner in the right sidebar on meta sites that one is visiting for the first time. (Presumably it indicates "Meta New User"?)

Some suffixes have since been removed in subsequent redesigns:

  • ?as - A link to a different Stack Exchange network site from the all sites section of the Multi Collider.
  • ?hq - A link to a question from the hot questions section of the Multi Collider.
  • ?sgp - A link created by the share button posted automatically to Google Plus.
  • ?__ - Contains a random value; used to switch between the full site and the mobile site.
  • Another one: ?noredirect=1 for migrated questions; having this in the URL on source site will show it instead of auto redirecting. Same for questions closed as duplicates, which by default redirect anonymous visitors to the duplicate. Aug 29, 2012 at 10:38
  • 4
    what's the meaning of the number? for example I got a url that ends with '?sem=2'. what does it mean?
    – Sparkler
    Jan 29, 2015 at 0:36
  • Jeff atwwood for twitter? Aug 30, 2015 at 13:37
  • 1
    It may be worth noting that links in the "Linked" section all have ?noredirect=1 (or rather, ?noredirect=1&lq=1) appended to them, regardless of whether they're actualy closed as duplicates/migrated (and regardless of whether you're logged in). The current answer is presumably accurate about what the purpose of the parameter is, but it doesn't state when/where it appears.
    – V2Blast
    Mar 28, 2022 at 16:09

We slap slugs onto links in places where we're looking for hard numbers about usage. Click through rates, visitors per share, that sort of thing.

It's a decidedly low tech approach that has a couple of benefits.

  1. No slow down
    • we're just querying our server logs for data, clients aren't executing anything special
  2. It's reliable
    • nothing's really running, so there's nothing to break and leave a user hanging
  3. It's visible, and trivially removable
    • cut the slug off, and you're not part of our stats anymore
    • personally, I find it sort of silly since you're hitting us anyway, but still it's a plus
  4. Easy to change
    • we just add/remove + "?blah=1" in the right places to turn this on and off

Offhand, I know we're looking at newsletter links, the site drop down, the hot question drop down, and shared links (Twitter, Facebook, Google+).

The data we collect can be used for figuring out whether certain features are worth keeping around or promoting. Sometimes it's just trying to measure the effectiveness of changes.

  • 10
    Can we have a list of these slugs?
    – nanofarad
    Aug 6, 2012 at 15:40
  • Sorry, I have to accept Rory's answer, as it has a list of all the links.
    – daviesgeek
    Aug 7, 2012 at 17:19
  • 2
    As for 2 and 3: given that sometimes those special links are copied and pasted into comments: are you sure to it's that obvious? Wouldn't statistics be better if an onclick handler would add the query parameters, but copying the URL would not? (I find myself removing the parameters quite often; would you rather have me leave it in place? Might be specific to Meta though.)
    – Arjan
    Sep 5, 2012 at 20:37

Actually, Kevin is correct. It's just to let Stack Exchange's staff know how are things going.

All sites in the dropdown menu have ?as=1 appended and all hot questions' links have got ?hq=1 appended

  • 10
    Clearly you were referring to Kevin's comment under the question, but at a glance this looks really insulting to Kevin Montrose, who posted an answer six minutes after you did.
    – Pops
    May 3, 2012 at 16:19
  • 2
    Eh, funny enough :p Added a link to the comment
    – Martin.
    May 3, 2012 at 16:48

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .