Britain's royal wedding broke records for live streaming on Friday, Internet firms said, causing some websites to falter under the strain as hundreds of millions watched online.
The marriage of Prince William to Kate, the Duchess of Cambridge, was streamed live on the British royal family's YouTube channel -- the first royal wedding to be covered in such a way.
Internet company Livestream, which is partnered with Associated Press, CBS and the Press Association, said the event broke its own records, with more than 330,000 concurrent viewers at one point.
"We are expecting the final analytics to show at least two million unique viewers throughout the service on livestream.com for the full ceremony," a spokesman said.
Akamai, a major traffic carrier, was handling nearly three million simultaneous viewers, breaking its record of 1.6 million concurrent live streams at last year's World Cup.
The BBC website, which was also showing live coverage, was struggling under the strain Friday morning, intermittently flashing an error message during the ceremony saying the site was experiencing "abnormal traffic".
"We are experiencing some technical issues with BBC Online due to the sheer weight of traffic, which may cause the site to be slower than normal in some cases," a spokesman said.
On Twitter, nine of the top 10 trending topics were related to the royal wedding. They ranged from the hashtags #RoyalWedding and #proudtobebritish to the words "They kissed".
"Royal wedding coverage" and "Kate Middleton wedding dress" were the two hottest searches on Google, which devoted the celebrated logo on its home page to the royal wedding and mapped the royal procession route in 3D.
The Google "doodle" featured a cartoon of Westminster Abbey with the fairytale couple riding in a horse-drawn carriage and linked to a page of search results on the royal wedding.
However fears that the global media event -- expected to draw two billion viewers worldwide and many of them online -- could "break" the Internet proved unfounded.
The royals have used the web extensively in the build up to April 29 to update the public on arrangements for the day, with channels on Facebook, YouTube and Flickr as well as the official Royal Wedding website, www.officialroyalwedding2011.org.
Palace officials hosted a live multimedia blog on the royal site, where visitors could congratulate the couple in an online wedding book and make donations to the Royal Wedding Charity Fund.
On Twitter, @ClarenceHouse provided live updates, while anyone wanting to send the couple a message could do so at #rw2011.
Meanwhile on the royal family's Facebook page, users could click "I'm attending" to register their interest and receive live updates.
Explore further: After a decade online, YouTube is redefining celebrity