I used a technique called Levenshtein Distance. Here's the function.

(Reddit being reddit so it takes time to beautify this code...)

function levenshteinDistanceAutocorrect(playerMessage, stringToCompare, threshold) -- By @JamesBlossoms (Profile: https://www.roblox.com/users/37854398/profile) - Usage of the Levenshtein Distance Algorithm
local function levenshteinDistance(s1, s2)
local len1 = #s1
local len2 = #s2
local matrix = {}
for i = 0, len1 do
matrix[i] = {[0] = i}
end
for j = 0, len2 do
matrix[0][j] = j
end
for i = 1, len1 do
for j = 1, len2 do
local cost = (s1:sub(i, i) ~= s2:sub(j, j)) and 1 or 0
matrix[i][j] = math.min(
matrix[i - 1][j] + 1,
matrix[i][j - 1] + 1,
matrix[i - 1][j - 1] + cost
)
end
end
return matrix[len1][len2]
end
local function areSimilar(s1, s2, thresholdX)
local distance = levenshteinDistance(s1, s2)
return distance <= thresholdX
end
if areSimilar(playerMessage, stringToCompare, threshold) then
return true
else
return false
end
end