Magnetic Switches Explained – Hall Effect vs TMR – HE Keyboards

Magnetic switch keyboards are the new hotness – basically every new keyboard hitting the market towards the end of 2024 and now at the start of 2025 are mag-switch equipped – but why? What’s so special about these things that’s making everyone and their dog build and buy them? Well, if you’ll permit an analogy, picture a controller – Xbox or PlayStation, you decide. I’ve got this Wolverine V3 Pro here so I’ll use that. A regular mechanical keyboard switch is like the ABXY buttons and bumpers – an on/off switch. Either it’s pressed and active, or it isn’t. On, or off. These magnetic switches are more like the joysticks or triggers. They can be on a little, on a lot, and anywhere in between. Why would you want that though? Well, knowing how far the switch has been pressed down means you can do a lot of interesting things. The most common features to find on these boards relate to the actuation point – going back to the control analogy, for FPS games that use the triggers to aim and shoot, sometimes you can change how far down you have to press the trigger before the gun fires, that’s the same as these switches. How far down you have to press the W key before you start walking forward, for example. For gaming, you might find you want to just barely press them to trigger for the fastest reactions and the snappiest movement, but for typing you might want to drop it down so you have to push them most of the way down so you don’t mis-type. With a mechanical switch how far down you need to press is fixed by the metal contacts inside the switch, but with magnets you get to change that – on the fly too. 

That adjustable actuation point can also be adjusted instantaneously, with a feature normally called Rapid Trigger. This basically moves the actuation point to some fixed distance below the current switch position. That basically means even as you lift your finger up, if you start pressing down again, even half way down the travel, the switch will trigger again. This is mostly useful for strafing in games like CS and Valorant, or if you are mad enough to play racing games with a keyboard, but it’s a feature you absolutely could not have without these switches. 

The other benefit to knowing how far down the travel you are is that you don’t actually have to only have one actuation point. A lot of keyboards – this Glorious GMMK 3 HE included – have a multi-action feature which lets you map multiple actions to a single key, depending on how far down you press it. The common examples are with the W key, where lightly pressing on it means you walk slowly, but full-pressing it means you sprint, meaning you don’t need to hold shift as well, or the other example is building in Fortnite, where with a single keypress you can open the build menu, build a wall or stairs, then close the build menu. Pretty handy, right?

Ok, so you’ve heard about all the benefits, but how the hell does the keyboard know where the magnet is? Well that’s where the HE part in most of these keyboard’s names come in. HE stands for Hall Effect, and that is the phenomenon where magnets induce a voltage in circuits just by being nearby. These hall effect sensors – the tiny black chips you see on this PCB here – have a voltage induced in them from the magnets in the bottom of the switches nearby, and turn that voltage into a signal that the keyboard can use to tell how far along the travel the magnet is. The closer the magnet, the larger the voltage, and therefore the stronger the signal. It’s really pretty genius, and these sensors aren’t exactly expensive. Even at consumer prices you are talking like 50p per switch, which to be fair is a decent bit more than a hotswap socket, but for this much more functionality I can see the value. 

The other benefit to just needing a little sensor on the PCB rather than a pinned connection is that these switches are completely separate from the PCB. They don’t even have pins in sockets, these are completely free floating which means you can much more easily make them hot-swappable, and because the switch is actually just a magnet in the stem, there is basically nothing to wear out and fail. Mechanical switches have a springy bit of metal built in – the actual switch part – and that wears out over time, eventually failing. These magnetic switches have no contact parts, and no switch mechanism to fail, so should be considerably more reliable. 

Now you might have heard about a new kind of magnetic switch – or actually in joystick form more likely – called TMR. That is short for tunnelling magnetoresistance, and is a pretty similar effect to HE, although it works slightly differently, and generally uses a different plane than hall effect sensors, but the key thing is that TMR sensors are generally more sensitive, more accurate, and especially for battery powered devices, they generally consume less power too. Now this isn’t going to magically double the battery life of your controller or TMR keyboard, but it should make a bit of a difference. The downside right now is cost. Hall Effect sensors have been around for decades, and as I mentioned earlier are readily available at commodity pricing, whereas TMR sensors are more rare, and therefore generally command a higher price tag. There are some devices that use TMR sensors already – in fact I’ve got a TMR keyboard on the way that I’ll be taking a look at in the next couple weeks, so stay tuned for that, but beyond that GuliKit offer TMR joysticks you can retrofit to your existing controllers and consoles.

For the most part though, magnetic switches – be that HE or TMR – offer a considerably better featureset than mechanical switches, and especially thanks to companies like Glorious offering not just plain linear switch types, but tactile, and yes even clicky switches, there’s no better time to get a magnetic keyboard. I know I am… Anyway, that’s how magnetic keyboards work, and the difference between HE and TMR sensors. I suspect HE will reign supreme for keyboards due to the magnetic alignment and the cost – a full size 104 key board needs 104 sensors, versus 4 for a controller, maybe 6 if you include the triggers too – but for battery powered devices like controllers, TMR will take over pretty quickly.