TMR vs Hall Effect switches

Same switch, different sensor

Both families put a magnet in the stem and read its position from the PCB:

• Hall Effect (HE): a Hall sensor outputs voltage proportional to magnetic flux. Proven, cheap, ubiquitous — every HE board shipped so far uses it.
• TMR (Tunneling Magnetoresistance): a sensor whose resistance changes with field direction via quantum tunneling. It is far more sensitive to small field changes and needs less current — which is why it took over gaming-controller thumbsticks first.

What that buys a keyboard: finer position resolution (smoother rapid-trigger curves at 0.01 mm-class sensitivity), better behaviour at the edges of the flux window, and lower sensor power draw — the last one matters mainly for wireless magnetic boards, where sensor current is a real battery line item.

What does not change

The compatibility logic in the checker — socket, polarity, keycap tolerance — applies unchanged. A TMR board is still an HE-style board to your keycaps.

Where TMR actually wins — and where it doesn't

• Wins: wireless magnetic boards (battery life), extreme-sensitivity rapid trigger, headroom against sensor saturation with very strong magnets.
• Doesn't: wired 60HE-style gaming. At 1–8 kHz polling the bottleneck is the game and the PCB, not the sensor physics. "TMR is faster" claims don't survive a stopwatch on wired boards.
• Ecosystem: still young. Cross-compatibility charts are thinner than HE's; vendors are only starting to publish dual-protocol switches (Gateron's Magnetic Jade Silent explicitly targets HE + TMR boards).

Buying checklist for a "TMR" board

1. Confirm the board actually has a TMR sensor per model — some lines mix sensor types across revisions.
2. Check which switches the board validates (socket + polarity), same as HE. Start from the board's shipped switch family.
3. Ask what you're buying it for: wireless battery life or analog feel → TMR is a genuine reason. Pure wired speed → any competent HE board is equivalent in practice.
4. If a dual-protocol switch exists for your board (e.g. Jade Silent), it removes the guesswork entirely.