Pope Francis' online flock has doubled from 2.5 million to 5 million Twitter followers in less than a month -- a third of the time it took his predecessor Benedict XVI to build up his following.
The account @pontifex -- the word "pope" in Latin -- has tweets in nine languages including English, Spanish, Arabic and Latin. They are snippets of religious instruction rather than insights into the pontiff's daily life.
The number on all nine accounts put together went over five million for the first time on Thursday.
The comments on the tweets left by followers are often irreverent and chatty, with one user asking the pope on Thursday: "How you settling in?"
Benedict launched the account on December 12 after encouraging Catholic Church leaders to use social media to reach a wider and more youthful audience.
The Vatican has said the tweets are approved by the pope although not actually written by him and are sent from a single computer to avoid hacking.
Francis' latest tweet on Thursday reads: "God loves us. We must not be afraid to love him." His first tweet a few days after his election read: "I thank you from my heart and I ask you to continue to pray for me."
On the night of his momentous election on March 13, the account had a single tweet reading "Habemus Papam Franciscum" ("We Have a Pope Francis").
The pope has shown a tradition-breaking style in his first few weeks in office and has said he wants the Church to be closer to ordinary people.
The number of followers on the Spanish-language account of Latin America's first pope has risen particularly sharply to 1.6 million, although the Argentinian was still trailing in Portuguese with 188,000 followers.
The pope's following is still a far cry from that of stars Justin Bieber and Lady Gaga -- with 37 million and 35 million fans respectively.
The 85-year-old Benedict sent the first papal tweet from a tablet during a general audience saying: "Dear friends, I am pleased to get in touch with you through Twitter. Thank you for your generous response. I bless all of you from my heart."
Several leading Vatican prelates are already regular tweeters including Cardinal Gianfranco Ravasi, head of the Pontifical Council for Culture.