The tech giant had to go back on its initial decision after facing severe criticism for removing pictures of a naked girl that has come to symbolise the atrocities committed during the Vietnam War.
After a global outcry, Facebook on Friday reversed its decision to remove postings of an iconic 1972 image of a naked, screaming girl running from a napalm attack in Vietnam.
The protests had started in Norway last month after Facebook deleted the Pulitzer Prize-winning image by Associated Press photographer Nick Ut from a Norwegian author's page, saying it violated its rules on nudity.
The revolt escalated on Friday when Norwegian Prime Minister Erna Solberg posted the image on her profile and Facebook deleted that too.
She then ran her own censored version of the image.
Initially, the tech giant stood by the decision, saying it was difficult to create a distinction between allowing a photograph of a nude child in one instance and not others.
This drew widespread criticism from social media users, many of whom thought Facebook was playing the role of an online editor.
But late Friday the tech giant said it would allow sharing of the photo.
"In this case, we recognize the history and global importance of this image in documenting a particular moment in time," Facebook said in a statement.
Politicians of all stripes, journalists and regular Norwegians had backed Solberg's decision to share the image.
The prime minister told Norwegian broadcaster NRK she was pleased with Facebook's change of heart and that it shows social media users' opinions matter.
"To speak up and say we want change, it matters and it works. And that makes me happy," she said.
The image shows screaming children running from a burning Vietnamese village. The little girl in the center of the frame, Kim Phuc, is naked and crying as the napalm melts away layers of her skin.
Phuc now travels around the world to speak against the horrors of war.
Several members of the Norwegian government followed Solberg's lead and posted the photo on their Facebook pages.
The issue had received global attention after Norwegian newspaper Aftenposten published the photo on its front page Friday.
It also wrote an open letter to Facebook founder Mark Zuckerberg in which chief editor Espen Egil Hansen accused the social media giant of abusing its power.
Hansen said he was "upset, disappointed — well, in fact even afraid — of what you are about to do to a mainstay of our democratic society."
The uproar also spread outside of Norway, with the head of Denmark's journalism union urging people to share Hansen's open letter.
Germany's Justice Minister Heiko Maas, who has previously clashed with Facebook over its failure to remove hate speech deemed illegal in Germany, also weighed in, saying "illegal content should vanish from the Internet, not photos that move the whole world."
More than 40 years after the picture was first published, the humble AP photographer Nick Ut credits it to his luck.
At the time, AP also had a discussion about the image because it violated the news agency's policy on full-frontal nudity.
Hal Buell, then AP's executive news photo editor in New York, said he received a message from Saigon photo editor Horst Faas saying a "controversial picture" was coming up.
"Maybe we discussed it on the desk for 10-15 minutes," said Buell, who is now retired. "But there is nothing about this picture that is prurient. How can we not publish this picture? It captures the horrors of war. It captures the terrible situation of innocents caught in the cross-fire of the war."
AP published the image and media worldwide used it, though some chose not to, Buell said.