UNC stands for Unified Naming Convention. It is a standard that checks how many of the expected executor functions an executor actually supports. A higher UNC percentage means more scripts will run without missing-function errors [citation:2][citation:10].
What UNC Measures
The UNC test checks whether functions like getgenv, setclipboard, and getrawmetatable exist in the executor's environment [citation:2]. It is essentially a checklist: does the function exist, yes or no.
There is also sUNC (sensible UNC), which goes further. It checks whether those functions actually work as intended, rather than just existing on paper [citation:5]. A faked function might pass a basic UNC check but fail sUNC.
Xeno's UNC Score
Third-party tracking sites list Xeno's UNC at around 84%, with sUNC at around 40% [citation:3]. Xeno's own support responses acknowledge that its UNC is lower than some internal executors, and explain the reason directly: Xeno is an external executor, which is structurally different from internal executors .
The developer's stated trade-off is stability. Xeno's lower UNC is presented as a deliberate choice that makes it easier to keep the executor working across Roblox updates, meaning it stays online more consistently .
Why External Matters for UNC
External executors do not inject a DLL into Roblox the way internal executors do. They rely on memory read/write and offsets to execute scripts. This design can make it harder to implement every UNC function at full fidelity, especially the more complex ones that internal executors handle natively.
What this means for you: If a script you want to run requires a very high UNC or sUNC score to function (common with scripts that use hooks or advanced environment manipulation), Xeno may not support it. For simple scripts and most game hubs, 84% UNC is often enough. If a script fails, check whether it lists a minimum UNC requirement.
Should You Care About UNC?
UNC matters if you plan to run complex scripts that depend on specific executor functions. For basic script execution and most popular game scripts, the difference between 84% and 100% UNC rarely matters in practice. The bigger factors for most users are attach reliability and whether the executor stays updated after Roblox patches.
Related Guides
Curious how Xeno's external design works? Read External Roblox Executor Explained. If a script fails despite a successful attach, see How to Fix Xeno Errors.