Hours after voting to leave it, Brits were frantically googling 'what is the EU' - and what would happen if they left it.

Call it Brexit remorse, but it seems online at least, many were showing they weren't quite sure what they were voting for.

And as the result sank in, so many people signed a petition asked for a referendum re-run, they crashed the website hosting it.

One of the top questions asked by UK users after the Brexit referendum result to 'leave' was released was "what is the EU?", Google Trends reported.


And queries about 'what happens if we leave the EU?' tripled.

Other spiking searches in the United Kingdom were queries for 'getting an Irish passport' and 'move to Gibraltar', the British territory on the south coast of Spain.

Google Search interest in the British pound - in free fall since the result - is at its highest level ever.

John Key addresses the media following England's historic decision last night to leave the European Union.

Twitter says some 6.4 million tweets were sent in the UK from the opening of polls Thursday through British Prime Minister David Cameron's resignation speech on Friday.

Meanwhile, tens of thousands of Brits want a do-over.

So many users were signing a petition for a re-run of Britain's referendum on European Union membership that they've crashed the House of Commons website hosting the document.

The petition passed the 200,000 mark on Friday evening, with a map of the voting indicating that most activity was in London - where most boroughs backed the "remain" camp in the referendum.

The House of Commons said it had seen "high volumes of simultaneous users on a single petition, significantly higher than on any previous occasion." A second referendum isn't in the cards for now, but experts say it isn't out of the question if those who back a British exit begin suffering from buyer's remorse.