Brexit was the top Twitter topic by some distance on Friday morning, generating more than 2m tweets and trending highest in countries across the world.
Social media users reacted with a mixture of surprise, gloating and wry humour.
The most retweeted post was from US whistleblower Edward Snowden, who said the referendum held lessons for people all over the world.
Several tweeters riffed on the plunging British pound.
Google reported a sharp rise in UK-based internet searches for ways of obtaining a passport for the Republic of Ireland, which is in the EU.
Sharp-eyed viewers of Fox News spotted that it initially reported that the UK had voted to leave the United Nations.
There was consternation among europhile cats.
One Canadian suggested a historical context.
Jokes in Pakistan and India focused on the potential for a flood of British migrants to the subcontinent and a possible hidden meaning in British singer Adele's lyrics.
War-weary Iraqis expressed wry surprise.
Lovers of schadenfreude - taking pleasure in someone else's misfortune - were treated to a new German compound verb - verschlimmbessern.
And could "Departugal" or "Czechout" be next?
'Those going to the UK to study will be pleased'
On China's Twitterlike Sina Weibo platform, the hashtag #UKEUReferendum# gained more than 85m views.
Some said the result showed the limits of democratic processes.
"The whole world is watching the Brexit vote. I think socialism is still the better system," one user wrote.
"Although a lot of people have mocked us for not having the right to vote and flaunted the democratic systems of other countries. Although our country's political system is not perfect, a referendum in China definitely wouldn't work. A referendum requires educated individuals with independent judgement," user Horse Dog God wrote, with a series of smirking emojis.
Some users started sharing the poster for the latest "Independence Day" film and wondering whether Scotland would vote to leave the UK.
Others had more personal concerns.
"Brexit brexit. Those going to the UK to study will be pleased - the pound is going to fall," user DaisyBucket said.