The Bible does not tell us how the Apostle John died, so we simply cannot know for sure how he died. However, we do have some accounts from tradition that may help us figure out how he might have died.
Most likely, based upon the accounts of tradition, the apostle John was arrested in Ephesus and was about to be martyred and killed. Supposedly, John was thrown into boiling oil. However, according to tradition, God miraculously saved John from death.
Afterwards, John was sent into exile to work as a slave in the mines of Patmos. While on Patmos, John had the vision that resulted in him writing the book of Revelation.
Eventually, John was released from Patmos, perhaps because of his old age, and he returned to the region that is currently Turkey today. He died peacefully sometime after AD 98 and was the only apostle to not die a violent death.
Papias of Hierapolis was a bishop during the. second century, and one commentary on Papias’s writings says that John was killed by a group of Jewish men. However, because this commentary may have misquoted or misread Papias, and because we do not have Papias’s writings directly, many people doubt the veracity of this theory concerning how the apostle John died.
Another legend says that John did not actually die, but ascended directly to heaven in the same way that Enoch and Elijah ascended to heaven. However, there is no evidence for this legend, and really no reason to believe this.
The apostle John was unique from all of the other apostles in that he alone lived to become an old man. Perhaps John was spared a violent death alone with the other apostles because it was God’s sovereign plan for John to write the book of Revelation, which was written later than the other canonical books.