The line counter that is included in file.au3 is incredibly slow, so I decided to make a new one. The way it works is really clever. The code is: Func LineCount($file) $thousands = 0 Do $thousands = $thousands + 1000 FileReadLine($file, $thousands) Until @error = -1 $thousands = $thousands - 1000 $hundreds = $thousands Do $hundreds = $hundreds + 100 FileReadLine($file, $hundreds) Until @error = -1 $hundreds = $hundreds - 100 $tens = $hundreds