CheckUser is an interface for users with the checkuser permission. An editor with CheckUser status on a wiki can in particular check if a user isn't a sockpuppet of another user on that wiki (not on all wikis). By using it, users are able to:
- Determine from which IPs a user has edited the Wikimedia wiki;
- Determine the edits on the Wikimedia wiki of a specific IP (even when logged in);
- Determine whether the user being checked has sent an email using MediaWiki interface to some other user. The time of the event is logged, the destination email address and user ID are obscured.
This information is only stored for a short period (currently 3 months), so edits made prior to that will not be shown via CheckUser. A log is kept of who has made which queries with the tool. This log is available to those with the checkuser-log permission:
* 08:52, 10 October 2011 CheckUser got IP addresses for Example (talk | contribs | block) (a very good reason for looking at their IPs) * 08:52, 10 October 2011 CheckUser got users for 127.0.0.1 (another good reason)
See the user manual for help.
Use of the tool
The tool is to be used to fight vandalism, to check for sockpuppet abuse, and to limit disruption of the project. It must be used only to prevent damage to any of Wikimedia projects.
The tool should not be used for political control; to apply pressure on editors; or as a threat against another editor in a content dispute. There must be a valid reason to check a user. Note that alternative accounts are not forbidden, so long as they are not used in violation of the policies (for example, to double-vote or to increase the apparent support for any given position).
Some wikis allow an editor's IPs to be checked upon his or her request if, for example, there is a need to provide evidence of innocence against a sockpuppet allegation; note, however, that requesting a checkuser in these circumstances is sometimes part of the attempt to disrupt.
Access to CheckUser
At the moment, only developers with access to the server can be granted CheckUser rights.
It is to be noted that an access to the server already makes it possible to know the IP of any user. Therefore, the CheckUser rights does not allow them to know more private data about users, but rather makes it easier to fight vandalism.
List of users with CheckUser
An uptodate list is available at .