Tafsir Al-Qur'an Al-Azim (“The Exegesis of the Great Qur'an”) was written by the 14th-century scholar Isma'il ibn 'Umar ibn Kathir Al-Basri Ad-Dimashqi (701–774 AH). It remains one of the most widely read explanations of the Qur'an, known for explaining each verse using the Qur'an itself, authentic sayings of the Prophet Muhammad (peace be upon him), and the earliest generations of Muslim scholars, rather than personal opinion.
This site presents that commentary verse by verse alongside the Arabic text and an English translation, for all 114 surahs, free to read on any device.