The details
- The G915 family uses Logitech's low-profile GL switches (Linear, Tactile, and Clicky). All three use the same stem, so one replacement set covers every switch option.
- The stem is not the standard Cherry MX cross mount. Any keycap set sold for MX-compatible switches, which is nearly everything in the enthusiast keycap market, will not attach.
- Replacement sets do exist. A handful of specialty vendors sell full G915 and G815 compatible sets in ABS and PBT, and single replacement keys are sold for repairing one broken cap.
- Caps come off with a gentle upward pull. Owners recommend pulling straight up from the corners rather than levering with a metal tool, since the low-profile stems are shorter and easier to crack than full-height MX stems.
- The G915, G915 TKL, G815, G913, and G813 use interchangeable keycaps, so sets listed for any of those boards fit the others.
Why standard sets do not fit
The GL switch was designed around a slim board profile, and the keycap mount is part of that design. The caps are much shallower than OEM or Cherry profile caps, and the underside socket is shaped for the GL stem specifically. Even low-profile caps made for other systems, such as Kailh Choc caps, are not guaranteed to fit, because low-profile switch stems are not standardized across brands.
Practical consequence: when shopping, ignore switch-type language like "fits linear switches" and look for the exact board model in the listing. A set that names the G915 or G815 will fit. A set that only says "low profile" needs closer inspection.
What owners actually do
The most common reason owners replace G915 caps is legend wear. The stock ABS caps polish to a shine and the paint around the backlit legends can wear through with heavy use. The popular fix in owner communities is a dye-sublimated or double-shot PBT set from a specialty vendor, which resists shine far better than the stock caps. The second most common purchase is a single replacement key after a cap cracks at the stem, which is a known weak point if caps are removed roughly.
If yours is a G915 X
Logitech's newer G915 X line is a separate design generation, and vendor listings state its keycaps are not interchangeable with the original G915 and G815. Vendors list G915 X sets separately for this reason. Check the exact model name printed on the underside of your board before ordering, and match the listing to that name.