If the question is which genre bucked the prevailing trend in publishing to record a notable increase in readership last year, the answer is clear: quiz books.
Spending on titles increased by almost a quarter in 2025, data from NielsenIQ BookData suggests. It was the best year for question books since records began in 1998, according to the company, which runs the ISBN and SAN agencies for the UK and Ireland.
There was also a sharp increase in spending on Bibles, with sales up 19% from the previous year. Industry research found that total sales of Bibles in the UK reached £6.3 million, an increase of £3.6 million on 2019 sales.
Waterstones and Amazon’s best-selling quiz books are spin-offs from the game show The 1% Club, broadcast on ITV and presented by Lee Mack. They are published by Transworld, a division of Penguin Random House.
However, spending on non-fiction fell to its lowest level since 2014, £791m, a fall of 5%. A total of 59 million books were sold, a year-on-year decrease of 6%.
Spending on adult fiction increased, although the number of printed fiction books sold fell slightly, by 0.5%.
Combined sales of printed books amounted to £1.81 billion. The data was published ahead of the London Book Fair, the publishers’ fair, which starts on Tuesday.
Philip Stone, head of publishing account management at NeilsenIQ BookData, said: “NielsenIQ BookData’s findings for 2025 reveal a resilient book market, with readers continuing to invest in stories despite a weaker year overall.
“Fiction continued to be the star performer, driven by strong growth in science fiction and fantasy, horror and graphic novels, while children’s and young adult books also recorded encouraging gains in key areas.
“Nonfiction faced greater pressure, although the popularity of trivia, quiz books and religious titles highlights the sustained demand for escapism and insight.”
The average cost of a book has reached record levels. It stands at £9.52, up 2% on 2024. The increase was attributed to inflation and the rising cost of book production.
Audiobook sales also increased, as did comics and graphic novels.
Game show host turned fiction writer and podcaster Richard Osman’s latest installment in the Thursday Murder Club series, The Impossible Fortune, topped NielsenIQ’s 2025 bestseller list.
It sold 478,000 copies, according to the data, ahead of Charlie Mackesy’s Always Remember and Freida McFadden’s The Housemaid.
Children’s author Julia Donaldson, best known for The Gruffalo, was the UK’s best-selling author, with 3.3 million copies purchased.
McFadden, which sold 2.6 million copies, adapted The Housemaid for a film starring Sydney Sweeney, which was released in December.
In third place was Dav Pilkey, author of the children’s series Captain Underpants, which sold 1.5 million.
Stone added: “With bestselling authors such as Richard Osman, Freida McFadden, Julia Donaldson and Dav Pilkey leading another strong year, publishers, booksellers and authors continue to keep the market full of energy, innovation and opportunity.
“The boost seems especially appropriate as we enter the National Year of Reading and work to inspire more people across the UK to make reading a regular part of their lives.”
