Who's On My Wifi notifies you about freeloaders

Martin Brinkmann
Jan 14, 2014
Updated • Jan 15, 2014


If your router supports wireless Internet and if WiFi is enabled, then it is theoretically possible that others connect to your network to use your Internet connection.

While you can make sure that it is harder for them, for instance by enabling the highest security mode or selecting a secure passphrase that needs to be entered to establish the connection, it can still happen that someone else may find a way to connect to your wireless network.

This ranges from trying various passphrase combinations over getting direct access to the passphrase to hacking into the network.

Either way, the result is that someone else is using your Internet connection for activities. If you are lucky, this means basic Internet browsing and maybe some legitimate downloads.

If you are unlucky, this means criminal activities, which range from spamming other users to harassment, hacking, or the distribution of malware.

That's why it is important to make sure that freeloaders are not connected to your wireless network.

The free version of the program Who's On My Wifi monitors your wireless network for connection attempts to notify you about new unknown connections.

Update: Please note that it requires the Microsoft .Net Framework. It is not clear which version though. A similar program without that requirement is Wireless Network Watcher by Nirsoft.

When you first start the application, you are asked to use the scan now button to run an initial scan of the network. The application detected the correct network IP range automatically on my test system, and scanned the whole subset in the process.

You can modify the IP range in the program preferences if that is not the case, or if you want to scan multiple IP ranges.

Every new device connection is classified as unknown by default. You can switch that to known and save the changes so that you are no longer notified when the device is detected on the network.

You can also add a name for each device besides setting its status to known, so that it is even easier to identify.

For each device found, its Mac Address, last IP address, last computer name, connection status, identification status, and description (custom name you pick) are displayed.

The free version of the program is somewhat limited in terms of what you can do in addition to that. According to pricing information on the developer website, it cannot be used to block intruders. In addition, it won't generate reports and only supports local notifications about intrusions.

What you can and should do however is change the WiFi password right away. And if you spot any configuration issues, such as no encryption or not the securest form of encryption, you should resolve those as well while you are at it.

You can make some customizations in the preferences though. The program scans the selected IP ranges in 4 minute intervals by default. You can change the interval to a minimum of 2 minutes or a maximum of 10 minutes.

Other options that you have are to disable the notification sound or window that pops up, to run network diagnostics, or to define when to check for program updates.

There are also mobile apps for Android and iOS that you can install and run instead.


While it is possible to find out if unknown devices are connected to your local network using tools that ship with Windows, it is less complicated to use Who Is On My Wifi for that.

The main appeal of the program is that you do not have to load the command line and run a command on it to find out about it whenever you want to scan the network.

Now Read: Six WiFi Security Myths


Tutorials & Tips

Previous Post: «
Next Post: «


  1. clas said on January 16, 2014 at 2:41 pm

    hi martin, just wanted to throw some cudos at cha…your use of the english language is really about the best i read each day. i do a lot of writing and so am conscious of grammar and spelling mistakes as i read. and you do really well. i see you are from germany…is english a first language?
    thanks again for all the “good stuff”

    1. Martin Brinkmann said on January 17, 2014 at 9:01 am

      No, English is not my first language. I still make lots of mistakes, as my eagle-eyed readers remind me every now and then ;)

  2. Dexter said on January 16, 2014 at 1:05 pm

    It uses .NET 2.0 to be precise (which is integrated with 3.0 & 3.5), you can check in Process Explorer (“.NET Assemblies” tab).

  3. joy said on January 16, 2014 at 12:25 am

    Found someone unauthorized access my wi-fi!
    What can do to remove that, i can’t touch router related so any software things that can remove the leecher?

  4. Who's On My Wifi said on January 15, 2014 at 5:18 pm

    Thanks for the write up!

    Yes, the software requires the .NET 2.0 framework which is included in .NET 2.0, 3.0, and 3.5

    If there is sufficient demand for a native win32/win64 edition that doesn’t require .NET, we may add it in the future. Right now, we’re very focused on getting out our router plugin edition so you don’t have to leave a desktop or server running to consistently detect intruders on the wireless.

    Thanks again for mentioning us!

  5. Mountainking said on January 15, 2014 at 6:05 am

    Great stuff Martin!

  6. Q said on January 14, 2014 at 8:13 pm

    The program Who’s On My Wifi depends on Microsoft .NET Framework and may not run without it.

  7. ilev said on January 14, 2014 at 4:26 pm

    The application is not portable.

    Portable Wireless Network Watcher at http://www.nirsoft.net

    1. Q said on January 14, 2014 at 8:13 pm

      A more direct reference:
      Wireless Network Watcher v1.70

    2. imu said on January 14, 2014 at 6:08 pm

      Thumb up! Portable plus can be run in Sandboxie no hiccup :)

  8. Dante said on January 14, 2014 at 4:05 pm

    But I like it when total strangers looking for freebies use my open wifi. Especially when they use their credit cards :)

  9. Question said on January 14, 2014 at 2:32 pm

    Totally OT.

    Hi Martin, is it possible to add alphabetical search on your site? There are so many important articles and it’s difficult to find them via simple search.

    1. Lanny said on January 14, 2014 at 5:42 pm
      1. Question said on January 15, 2014 at 12:11 pm

        No, I meant simple A,B,C,D,E…. page where if you click on “A” you find things like Avira anti-virus and so on.

      2. Martin Brinkmann said on January 15, 2014 at 12:29 pm

        You mean only programs? Check out this one: https://www.ghacks.net/best-windows-software/

        It may not be all, but it may come close.

    2. Martin Brinkmann said on January 14, 2014 at 2:35 pm

      I’m not sure if something like this exists for WordPress to be honest. I look around.

      1. Question said on January 15, 2014 at 12:55 pm

        Yes, what you posted as an example (microsoft programs) is much more helpful, it will be nice if you can sort out articles like that in a separate page. So many times it happened that I’m looking for some old article without any or little chance to to dig it out. Thanks.

      2. Question said on January 15, 2014 at 12:39 pm

        Hi Martin, for some reason I couldn’t reply on your new post so I will reply here.

        No, not only programs, for example “DonationCoder” could be under “D”, or Wifi under “W” and so on. I hope it is possible to do it without too much hassle cause it’s a pitty how some great articles are getting buried by new posts.

      3. Martin Brinkmann said on January 15, 2014 at 12:48 pm

        It is not possible to automate this, I think. It may be possible using tags, but that too would require quite the sophisticated plugin. I check, but cannot promise anything.

Leave a Reply

Check the box to consent to your data being stored in line with the guidelines set out in our privacy policy

We love comments and welcome thoughtful and civilized discussion. Rudeness and personal attacks will not be tolerated. Please stay on-topic.
Please note that your comment may not appear immediately after you post it.