The actress, who played Monica Geller in the hit comedy, has given her review after starting season one: "It's really good."
Despite finishing in 2004, Friends remains one of the most popular shows on TV.
Also starring Jennifer Aniston, Matt LeBlanc, Lisa Kudrow, Matthew Perry and David Schwimmer, the show features 236 episodes - so a lot of entertainment to beat boredom during the lockdown.
Cox spoke about her binge-watching during a stripped-back version of Jimmy Kimmel's late-night show, which is off air due to the pandemic, saying the series that made her famous is keeping her occupied through the shutdown in California.
Appearing via video link from home, the star said she had bought all 10 seasons of Friends on Amazon Prime, as the series has been taken off Netflix ahead of the HBO Max launch of the long-awaited reunion special show.
"I decided during this time, people love the show so much, I decided to binge watch Friends," she said. "I just started season one - it's really good!"
So while Aniston is sharing isolation videos with her dog, Cox is reminiscing.
However, the actress 55, admitted her memories of being on the Friends set are a bit hazy.
"I don't remember even being on the show, I have such a bad memory," she said. "I remember obviously loving everybody there and having fun and I remember certain times of my life I was there but I don't remember episodes."
So Kimmel decided to put Cox to the test, making her go head-to-head with his cousin, a big Friends fan. But to make it easy, all the questions were Monica-related.
The score? Cox was beaten 5-0.
Questions to which she did not know the answer included the identity of Monica's first kiss and who urinated on her leg in the season four episode The One With The Jellyfish.
Clearly, she needs to brush up on her knowledge - at the minute, she probably wouldn't fare to well taking our ultimate Friends quiz.
During the interview, Cox confirmed filming for the much-hyped Friends reunion had been due to take place this week, but was postponed due to the coronavirus crisis.
However, the reunion is still slated to be available at the launch of the HBO Max streaming service in May.
Cox also used her appearance on Kimmel's stream to ask viewers to make a donation to the Meals On Wheels charity.