The advent of the always-on internet connection has transformed modern computing. While you’re away from the keyboard, your software can automatically update itself, fixing bugs and patching security flaws. Or automatically back up data from your hard drive to a remote server so that, in the event of disaster, you still have a record of even your most recent work. Distributed computing applications like [email protected] and [email protected] allow you to contribute your computer’s processing power, while you’re not using it, to solving computation-intensive problems like identifying extraterrestrial transmissions and understanding complex biomolecules.  There’s all kinds of good stuff your computer can do with that internet connection, while you’re away.

It can also, of course, get into lots of trouble. Backdoors, bot-nets, spyware—the list goes on. And while the good guys may allow you to configure their off-hours internet usage in software, and will probably respect your choices, the bad guys won’t.

If you want to be double-dog sure, here’s a simple, fool-proof answer: a hardware kill switch. Put one on the wired connection between your computer and router and use it to unambiguously isolate that computer from the internet whenever you want. Or put it between your router (wireless or otherwise) and your ISP hardware to control the connection for the entire house. Sure, you could just unplug the cable, but that’s hard on the connectors, and the switch is faster to use and neater-looking, to boot.

And it couldn’t be much easier to build. We’ll show you how to build an unobtrusive basic Internet Kill Switch, and then an over-the-top “dramatic version” that’s a bit more fun to make and use.



Step #1: Install the jacks.

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  • Using a small screwdriver, snap the cover off the surface mount box.
  • Snap the first RJ-45 jack into place on the surface mount box front panel.
  • Snap the second jack into place.

Step #2: Make the first connection.

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  • Separate the jacks / front panel assembly from the surface mount box baseplate.
  • Separate the 4 twisted pairs from the network cable scrap. Discard the outer cable sheath and any reinforcing fibers within. Untwist the pairs.
  • Use the punchdown tool bundled with one jack to connect the wires from the "green" pair to the color-coded terminals indicated by the "A" coded jack labels.

Step #3: Finish the jack wiring.

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  • Run the other end of the wires to the matching color-coded "A" terminals on the other jack, and connect as before with the punchdown tool.
  • Repeat for blue and brown pairs.
  • Connect the wires from the orange pair, as before, but route the solid orange wire up and away from the others, as shown.

Step #4: Drill switch mount.

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  • Use a pencil and ruler to locate the center of the surface mount box cover with intersecting tick marks.
  • Drill a small 1/16" diameter pilot hole at the intersecting pencil marks.
  • Drill out the pilot hole to the diameter of your switch's mounting barrel.

Step #5: Wire the switch.

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  • Clip the orange wire, right in the middle, between the 2 jacks. Strip about 1/4" of the insulation from each cut end.
  • The switch will be ON, and the orange leads connected, when the switch handle leans away from the 2 soldered contacts. As shown, the switch is in the ON position.
  • Solder one of the cut, stripped leads to the switch's center terminal. Solder the remaining lead to one of the other switch terminals.

Step #6: Assemble.

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  • Snap the box front panel back into the baseplate, and lower the cover into place. Direct the switch barrel through the mounting hole you drilled earlier. Secure with the switch's bundled hardware.
  • Snap the surface mount box cover back into place on the baseplate.
  • Test the project by inserting it between your computer and your computer's internet connection, and trying the switch. Make a label to indicate OFF and ON positions. Fix the label in place using the box's bundled label cover.

Step #7: Give it some drama (optional).

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  • Killing the internet is not to be taken lightly! So we popped out the jacks and front panel and mounted them in this serious-looking black RadioShack enclosure, #270-1803. Part #270-135 is also a good fit. Cut a hole to accept the panel, using a strong utility knife or a high-speed rotary tool with cutoff wheel. Then snap the panel in.
  • TIP: Enclosure #270-1803 has internal ribs that help the panel snap in tightly, if you line up the hole just right.
  • Then we swapped the switch for this awesome toggle with a big red safety cover, RadioShack #275-601, to prevent any disastrously untimely switchings-off of the internet. Drill a mounting hole to match your switch's barrel, and mount it with its included hardware. With the cover closed and the switch in the down position, the switch should be closed (and the internet connected). If your switch is open in this position, just loosen the hardware and rotate the switch 180°.

Step #8:

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  • Finally, we added a big dramatic label to clearly announce the importance of our Internet Kill Switch.
  • Grab this PDF and print it at 100%. Trim with scissors and affix it to the enclosure with your adhesive of choice.


Internet Kill Switch - John Edgar ParkTo use, mount the switch box using the bundled screws or double-sided adhesive foam. Connect your computer (or router) to one side of the switch, and your router (or ISP equipment) to the other. Click! Goodnight.
John Edgar Park

John Edgar Park

John Edgar Park likes to make things and tell people about it. He builds project for Adafruit Industries, Boing Boing, and Make. He has ninja warrior goals. You can find him at and twitter @johnedgarpark

Sean Michael Ragan

Sean Michael Ragan

I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and My work has also appeared in ReadyMade, c't – Magazin für Computertechnik, and The Wall Street Journal.

  • Superhotdog

    Way Cool!

  • Mike


  • How about an auto wifi kill switch? Long story behind this Q, but basically my computer is on high speed connection BUT it’s been/is being “bugged” via wifi either by a piggy-back on someone around me or a hidden modem somewhere near. Long, 10 year, 5 different houses/apartments later, and still being surveilled by a group of VERY, upsettingly adept people who are pros. ANY ideas would be helpful.

  • RJ-45 wall jack or just a normal rj-45

  • Shortz

    How about a pressure switch under your seat so the (your) internet is up only when your but is down?

    Or- wire it up the kill switch box to a 120V relay, then plug the relay’s coil (using a re-purposed power cord) into a SensorPlug ($15)- it will automatically turn it off when it no longer sees motion. I’d put an over-ride switch on the box that sits on your desk so you can decide to keep it on for a long download or when streaming music – BUT wire a self blinking LED like these that you can easily power from a re-purposed USB cable. This will remind you that you have over-ridden your primary auto-off feature.

    Dang it! Now I have another project on my list.

  • Shortz

    Seems like a good idea for a kit for MakerShed, no?

  • sa

    That is great. Analog living takes charge :-)

  • tim dolan

    I suggest that you test the wiring by plugging it into a system before installing the switch. Build a little, test a little, learn a lot.

  • I’ve forwarded this to our office IT manager so he can get installing one asap :)

  • I didn’t like the white jacks, and it didn’t feel old school enough. I think I’ve made some improvements:

  • Uh… ok, but why not just put your internet on a power strip and just turn off the power?

    • Hartwell

      Because that is to easy and not fun.

  • ニクソン オメガ 時計 種類

  • Jesse

    Since both orange and green are used for RX and TX depending on whether you use T568A or T568B, would it not be prudent to use a DPDT switch to kill both RX and TX to prevent either up- or download?

  • Or you can get the one i use here..

    Prevent Identity Theft


    This works great for me, it was cheap..

  • Maxillius

    I’ve got my router, hub and cell antenna plugged into a single power strip. I want it disabled, it’s disabled. Each computer is on its own power switch as well. Switching them off at the wall isn’t the best thing for components, but in an emergency it makes all the difference.

  • Beelzebob

    I’ve been using a kill switch since I first got on broadband, but instead of building one I just use an A/B switch. A=internet B=null. Simple, quick and serves the purpose. You can get a mini push button switch for RJ-45 cables for less than 5 bucks, shipped, or one with a knob for $10-15.

    My thought is that while firewalls and good security are vital, completely disconnecting from the internet is the only true way to prevent incursions when you are not going to be using it for a while. You can turn off your computer or router to accomplish the same, but both take time to reboot. Switches, like the project depicted here or one purchased from the store, are virtually instantaneous and are a much better fit with my computer lifestyle.

  • FlyAway

    I simply turn off my cable modem

  • For the People

    Just FYI, on certain cables you’ll find that the striped orange wire is the one to solder. I’ve found most use orange, but there are a few that use the striped. No idea why? If anyone has info on that, it would be appreciated.

  • Chris Brown

    Just seen this online. Internet kill switch,

    I ordered two.

  • Talha Ejaz

    Just wondering is there any kind of program that could mess up wifi signal in my room for sometime. People are always coming over in my room apparently i got good signals

    • tjpc3 The Redstoner

      You can with a signal jammer but it’s not very legal as it can disrupt other signals within a very large radius. However most routers have the option to allow allow only a specific set of MAC addresses to connect to them. Since every computer has a unique MAC address (actually every ethernet adapter) with some tinkering and googling you should be able to make it so only you and anyone you specify be able to have access to your wi-fi.

  • Josh McNattin

    Thanks for this. My previous cable modem had one built in, but not my new one. After hearing about Comcast’s plans to cap monthly usage, my recent introduction to watching Twitch regularly and using GlassWire to keep track of my bandwidth (seeing how much is going down the drain with “idle” usage on browsers, etc), I figured I should shut off my internet while away, even if I don’t shut my PC down completely.