# Are M-LOK and KeyMod accessories interchangeable?

**Verdict: No**

No. KeyMod uses a keyhole opening and M-LOK a rectangular slot with a rotating T-nut. Neither system’s hardware mounts to the other.

They are two separate attachment standards that solve the same problem in incompatible ways. No KeyMod accessory mounts directly into an M-LOK slot, or the reverse — the hardware simply does not engage. What does exist are small adapter sections that bolt into one system and present the other, so a KeyMod accessory can reach an M-LOK rail through an intermediate part. That is a conversion rather than interchange, and it adds height and a second interface to check.

- **KeyMod slot** — Keyhole — insert through the round end, slide, tighten
- **M-LOK slot** — Rectangular — T-nut drops in and rotates 90 degrees
- **Direct hardware interchange** — None — needs an adapter section
- **M-LOK origin** — Developed by Magpul
- **Practical default** — M-LOK — far wider industry support today

If you are choosing rather than matching something you already own, M-LOK is the safer bet: it has the broader accessory ecosystem, and KeyMod support has thinned considerably. If you already have a KeyMod handguard and a drawer of KeyMod mounts, there is nothing wrong with it — just buy hardware that matches the rail in front of you.

> **Caution:** Check the slot shape on the handguard before ordering, not the product title. Listings routinely describe a handguard by the wrong standard, and the two are unmistakable once you look at the openings.

## Sources

- [Magpul M-LOK — the standard and its hardware](https://magpul.com/m-lok)
- [M-LOK — origin and technical description](https://en.wikipedia.org/wiki/M-LOK)

## More on AR-platform parts

- [Will an AR-15 upper fit an AR-10 lower?](https://www.tactgpt.app/answers/ar15-upper-on-ar10-lower.md)
- [Will a mil-spec AR-15 stock fit a commercial buffer tube?](https://www.tactgpt.app/answers/mil-spec-stock-commercial-buffer-tube.md)

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Last checked 2026-09-02. TactGPT can make mistakes. Always check important info for accuracy. The information it provides is intended for educational purposes only. It does not give legal advice; verify any laws cited. Always follow all applicable laws and safety guidelines.

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