The website, which offers an interactive reading experience of the Harry Potter series, was made available to one million Beta testers following its unveiling last June.
Pottermore was due to become accessible to all in October, but a statement has now revealed that its launch was put back when the "overwhelming demand" from Beta users demonstrated that changes would need to be made for the site to function properly.
"We always knew Pottermore would be incredibly popular," the release read. "We wanted to make sure that we had a really good understanding of how people want to use the site and which bits we'd need to modify before giving more people access.
"We gathered some incredibly useful feedback from our Beta users, and it became clear that our original platform wouldn't be suitable when millions more users came on to the site.
"So we made a big decision: to move Pottermore to an entirely different platform set-up. This 'invisible' change has involved a lot of work behind the scenes but it will enable our users to get the best from Pottermore as it grows and develops."
The statement accepted that there "have definitely been some challenges" in putting Pottermore together, but promised users that the finished site would be worth the wait.
"Over the coming weeks and months we'll be adding exclusive content and many more exciting features (such as sounds) to Pottermore for you to explore, share and discover," it said.
In a Digital Spy poll launched after the announcement of the site last year, over 66% of voters said they were excited to experience Pottermore.
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