According to the Guinness Book of Records and many other sources including wiki, the Holy Bible is the best selling book of all time, nothing else compares.
Research conducted in 2021 estimated that there had been printed and circulated between 5 and 7 billion copies of the bible.
Bibles are printed with an annual rate of 80 million copies per year.
One huge milestone in the history of the Christian Bible came in the early 19th century when the first Bible Society's were founded. These society’s ordered Bibles in such huge quantity’s and either gave them away or sold them at cost price to spread the word.