Hall effect sensors are everywhere right now. Keyboards, game controllers, and DIY kits use them for more precise inputs. But with any newly popular device, it can be easy to immediately jump onto the hype and assume that a new technology is better without knowing the advantages.

As a mechanical keyboard hobbyist who has also reviewed peripherals employing Hall effect sensors, I’m excited by the technology. I’m here to help you answer all your questions, whether you’re deciding to upgrade or just want to know what Hall effect means.

What Is the Hall Effect?

The Hall effect is a principle of magnetic fields discovered by Edwin Hall in 1879. He found that placing a magnet next to an electrical current flowing through a conductor would cause the electrons to move with the magnet’s position. This affects the current’s voltage as the electrons are pushed to either side of the conductor. The resulting changes in the voltage can be measured to determine the distance of the magnet from the conductor.

Put more simply, moving a magnet closer to an electrified piece of metal will cause the electric current to react, and this reaction can be measured. A Hall effect (HE) sensor measures this change in voltage and returns a value to the computer.

This principle is utilized in countless technologies today across multiple fields. One of the most common uses is in a car’s wheel speed sensor. These sensors utilize the Hall effect to measure the rate at which a wheel is rotating, which is then reported back to the car to control things like cruise control, ABS, and speedometer.

Hall effect sensors have been used for decades in computer technologies too. Honeywell produced the first Hall effect keyboards in the 1970s and ’80s, but the technology eventually fell out of favor as more cost-effective keyboards became widespread. It only began resurfacing in the 2010s with manufacturers like XMIT producing small batches of modern HE keyboards.

Hall Effect Advantages in Peripherals

The largest improvement Hall effect sensors offer is response time. Because an HE switch relies on magnets instead of physical contact to register an input, it can theoretically register information far faster than a keyboard’s traditional mechanical switch. This is one of the main reasons HE switches are popular in esports and competitive gaming, where milliseconds matter.

For the average keyboard enthusiast, an HE switch’s most impressive feature is how the sensor registers user input. A traditional mechanical switch will only return two binary values of “on” and “off” at static positions. It will tell your computer when a switch is being pressed past a certain point but doesn’t provide any other information. A Hall effect switch, on the other hand, can return a multitude of numbers that correlate with the switch’s position. These values range from near the top of the switch, through the middle of the keypress, all the way to fully compressing the switch. As a result, the computer will know exactly how far the key is being pressed down and can provide variable inputs based on this information.

This lets you adjust the point at which a switch activates. If you want the switch to immediately register a keypress when you start to press, it can do that. If you want to wait until the key is entirely pressed down before anything happens, that can be done as well. This can be used to prevent mis-inputs or to provide multiple inputs from the same key, such as a half-press being programmed to walk in a game, and a full press being programmed to run.

On a traditional mechanical keyboard, there is a predetermined distance, called the actuation point, where a key registers that it is pressed. If the switch is above this location it will never return a signal, and if it’s below this location it will always return one. With a Hall effect switch, you can instead detect the direction the switch is moving in. This enables a feature commonly referred to as “rapid trigger,” where quickly pressing a switch after it stops moving will cause the keyboard to register another input, even if it hasn’t returned to the initial actuation point yet. This, combined with the lower latency of HE switches, allows for much faster reaction times in games since the keyboard’s inputs are determined entirely by your movement.

Along with all of this, Hall effect sensors are completely contactless. Their activation is determined by the distance between a magnet and a piece of metal, so nothing needs to make contact for them to register a keypress. Compared to a mechanical switch, where two pieces of metal are pressed together to complete a circuit, a Hall effect switch can potentially have zero friction. That makes them incredibly smooth to type on. The lack of physical contact also means Hall effect switches can last an incredibly long time over mechanical switches, with some exceeding 100 million actuations.

Hall Effect Sensors in Controllers

Some video game controllers utilize Hall effect sensors to create more precise and longer-lasting joysticks. These controllers became more prevalent after first-party controllers from Nintendo, Microsoft, and Sony started to suffer from “stick drift,” an issue where potentiometer joysticks slowly started to fall out of alignment and register movement even when the stick was not being touched. Stick drifting typically occurs after a few years of consistent use, meaning the device will likely be out of warranty by the time it’s noticeable.

Along with controllers, you can also purchase Hall effect joysticks for existing systems. One of the most popular is GuliKit’s drop-in Hall effect joysticks drop-in Hall effect joysticks for the Nintendo Switch. These can easily be swapped into standard switch Joy-Cons with a screwdriver, patience, and some repair know-how. Besides this, there are similar kits for other devices along with full controllers that come stock with HE sticks.

These sticks are impressive: They’re precise, reliable, and incredibly smooth to use. While they aren’t as customizable as Hall effect switches in keyboards, they have proven over the years to be incredibly robust and reliable. However, they aren’t without downsides. A set of two will typically be at least $20, you’ll probably void the factory warranty during installation. But if you’re already dealing with stick drift, an upgrade kit might be preferable over sending your Joy-Cons out for repairs or spending $80 on a new set that will eventually start to drift.

The Disadvantages of Hall Effect Sensors

The largest downside of Hall effect keyboards is the price. While not massively more expensive than equivalent non-HE keyboards (Keychron’s HE models typically cost $20 or $30 more than the mechanical switch variant), the technology is typically only offered on more premium models. Reputable Hall effect keyboards start around $130 but can surpass $200 for more premium models or larger layouts.

Hall effect keyboards can be endlessly tweaked using software, but they are relatively limited in physical customization. Since modern Hall effect keyboards are a relatively new technology, they are not very standardized. This means different HE switches will not necessarily be swappable between keyboards, and new switches introduced in the future will likely not be compatible with keyboards produced today. Compare this to traditional MX-style mechanical keyboards, where there are hundreds of directly compatible switches available. It will feel like your aftermarket options are limited, especially when the vast majority of HE switches available today are linear.

They may not be as refined as existing technologies, and models that don’t catch on may end up being left in the past without firmware updates, bug fixes, support, or replacement parts—a fate already suffered by countless once-promising devices.

Another important detail to note is that something being “Hall effect” does not automatically mean it will perform better than existing devices. High-performance mechanical switches or potentiometer sticks still perform incredibly well, and some budget Hall effect peripherals will still cheap out on materials, quality control, and manufacturing tolerances. It’s still just as important to research and seek out multiple opinions as it would be with any other product, and not assume something is good purely because it uses all the latest buzzwords.

Power up with unlimited access to WIRED. Get best-in-class reporting that’s too important to ignore for just $2.50 $1 per month for 1 year. Includes unlimited digital access and exclusive subscriber-only content. Subscribe Today.