Optical vs Mechanical Keyboard Switch Compatibility: Can You Swap Them?

Usually, no: an optical switch will not work in a standard contact-based mechanical keyboard, and an MX-style mechanical switch will not normally work in an optical keyboard. Compatibility depends on the keyboard’s sensing technology, PCB and switch socket—not just how the switch looks or how many pins it has. Check the keyboard maker’s compatibility guidance before buying replacements.

Why optical and mechanical switches differ

A conventional MX-style switch registers a keypress by bringing electrical contacts together inside the switch. In an optical design such as Gateron’s KS-15, the keyboard detects a change in an infrared light path as the switch stem moves. The PCB therefore needs the appropriate optical sensing components and circuitry; a contact-based PCB is not made compatible simply because a switch can be pushed into its socket. Gateron KS-15 product information describes its infrared sensing and says the switches are not compatible with regular mechanical keyboards. CHERRY’s MX2A Red specification, by contrast, identifies a mechanical switch with electrical contacts. CHERRY MX2A Red technical data

A simplified view of the sensing difference

Conceptual diagram—not to scale: Gateron KS-15 optical: IR emitter → light path through switch → sensor ↑ moving stem interrupts light CHERRY MX2A Red: moving stem → metal contacts meet → circuit closes The first arrangement needs optical sensing on the keyboard PCB; the second uses electrical contacts in the switch. This illustrates these named examples, not every optical switch design.

Does the pin count make an optical switch compatible?

No. Pin count is one part of physical mounting compatibility for some contact-based switches; it does not tell you how a switch sends a keypress signal. Even when a switch appears to fit, its sensing method and the PCB’s electronics must match. A hot-swap socket only means a supported switch can be removed without desoldering—it does not make different sensing systems interchangeable.

Not all optical switches share the same design

“Optical” describes a sensing approach, not one universal switch shape or standard. For example, Gateron says its KS-22 optical switch should not be used as a replacement for the KS-15. So even a switch made by the same brand and labelled optical may not fit or function in another optical keyboard. Check Gateron’s KS-22 compatibility note before treating one optical switch as a substitute for another.

What to check before ordering replacement switches

1. Find the exact keyboard model and revision. Check its manual or manufacturer support page for the supported switch family.

2. Confirm the sensing technology. Look for terms such as optical, contact-based mechanical, or Hall effect; these refer to different systems.

3. Check the precise replacement model and PCB or socket compatibility. Do not rely on appearance, pin count, or the word “hot-swappable” alone.

4. If the documentation is unclear, ask the keyboard manufacturer before removing switches or placing an order.

If your keyboard is designed for standard MX-style contact switches, choose replacements explicitly listed as compatible with that keyboard and PCB. For help comparing switch types and available specifications, explore our mechanical keyboard switch database—then verify your shortlisted switch against the keyboard maker’s compatibility information before buying.