getfunctionhash.mdx

title	getfunctionhash

Returns a deterministic hash of a Luau function's compiled body as a hexadecimal string.

getfunctionhash(func: function): string

The hash covers the function's compiled bytecode instructions together with its constants. Two functions that compile to the same body with the same constants produce the same hash; changing a single constant changes it.

Most commonly used to fingerprint a function so a later hash mismatch reveals it was hooked or replaced, or to confirm a clonefunction copy still matches the function it was cloned from.

Parameters

Parameter	Type	Description
func	function	The Luau function to hash.

Returns

string - a 96-character hexadecimal string (SHA-384 over the bytecode and constants). The same function hashes to the same string on every call, and the value stays stable across sessions while the function's code is unchanged.

Example

In an RPG Roblox game, fingerprint a Luau function you located and re-check it later, so you notice if the game swapped it out from under your hook.

local hash = getfunctionhash(print)

local target = filtergc("function", {Name = "PurchaseFruit"}, true)
local baseline = getfunctionhash(target)

task.delay(30, function()
    if getfunctionhash(target) ~= baseline then
        warn("PurchaseFruit was replaced - re-apply your hook")
    end
end)

Comparing function hashes is a fast way to verify function integrity.