There are different documents of Qur'an available in different localities which discredit various claims for varity of reasons. Please read Layth Al-Shaiban detail research on Qur'an.
"All Muslims are taught from a very early age that the Quran is a perfectly preserved book and that God has taken it upon himself to guard each verse, word, and letter of the Quran from any errors or changes:
“Indeed it is We who have sent down the Reminder, and indeed it is We who will preserve it.” (Quran 15:9)
However, one of the least discussed or debated subjects amongst Muslims and even amongst students of the Scripture are the variant texts of the Quran, namely: Hafs & Warsh."
