2020 is that year that brought unexpected situations, events, and changes in almost every aspect of our life. And the world of writing – from the book genres to reading and publishing does not make any exception.

Due to the COVID-19 crisis, multiple lockdowns, and social distancing measures, people were forced to move dramatically towards the online channels, both for the purchase of various goods and entertainment. As a response, many industries had to take massive, urgent, and previously unthinkable actions to move into the digital world, too. A McKinsey Global Survey shows that COVID-19 has accelerated the adoption of digital technologies by 7 years globally, while the situation is not much different by geographical region.


However, unlike many other industries, the publishing world has faced these changes for almost a decade now. According to the recent data provided by Statista, a total of 191 million e-books were sold in the United States in 2020. The sharp increase of 21 million e-books sold in just one year (2020 compared to 2019) could be the direct result of the coronavirus outbreak, which led to a large growth in online media consumption.

Direct access to bookstores was one of the last big advantages of the traditional publishing houses, but it has now been lost due to blockages around the world and to the public’s effort to stay home whenever possible.

This is good news for the online bookstores and self-publishing platforms, and bad for physical libraries. In addition to the social distancing measures during the Coronavirus crisis, many other factors influence the increased adoption of the e-book market and the publishing industry trends:

  • The constant sophistication and technical development of reading devices provide an experience similar to that of reading a paper-printed book and are the key factors influencing the global e-book market. Increasing the use of smartphones, tablets and the multilingual feature of e-books is an essential advantage that determines the increased global demand for e-books.
  • Online applications or services provide easy access to a wide range of e-book libraries, thus emerging as cheap alternatives to the traditional method of delivery. The services available for these e-books, such as e-loans, have also supported the adoption of e-books worldwide.
  • Publishers and libraries are also noticing increasing demands for e-books. Hachette Book Group, one of the major publishers, announced that in 2019 the publishing company generated EUR 2.38 billion, representing a 5% increase over 2018.
  • Environmental protection campaigns by governments around the world, especially to reduce paper consumption and save trees, also increase the demand for e-books.
  • Libraries around the world have closed most of their services to mitigate the spread of COVID-19. But many of them still offer access to reading electronic materials. Besides, due to the low cost of e-books, librarians can now buy more copies, thus contributing to market growth.

In those circumstances, it’s not a surprise that smartphones have become even more of a lifeline than before. A recent We Are Social research reveals that 5.22 billion people all over the globe use a mobile phone, representing an increase of 93 million since January 2020.

best-selling book genres 2021 - We Are Social

All these data suggest that content for smartphone users is a great focus for your digital publishing efforts this year. However, the same report indicates that around 66% also use laptops or desktops for browsing and reading, meaning you shouldn’t ignore other platforms.

Anyway, it doesn’t really matter how people access the books. The most important thing is that, regardless of their format – from hardcovers to softcovers to e-books and audiobooks, bestsellers belonging to all book genres manage, in one way or another, to reach their readers in all corners of the globe.

Thus, it seems the pandemic hasn’t changed just the way people read and buy books, but it also affected the book categories, because since 2019:

  • nonfiction for young readers saw the most increase in the book publishing industry, maybe also because the schools were closed and much of the education happened at home
  • books about social issues and social justice also gained popularity in 2020
  • for childrens’ nonfiction categories, education/language/references, and hobbies/games/activities were the most popular subcategories.

Still, no matter how trends change in one context or another, several book genres typically produce bestsellers, and at least for 2021 are trending categories.

Best-selling book genres in 2021


In terms of book sales, romance novels are one of the most popular genres of fiction books. As human beings, we look for love stories and romance book lovers invest a lot of money in their reading habits. That’s why romance fiction is a billion-dollar genre, with estimated sales of $1.44 billion including self-published titles in 2016 – according to Bookstats. In addition, the Author Earnings’ annual report shows that in the last nine months of 2017, were sold 50,957,116 units of romantic e-books for a total value of $ 162,028,816.90.

However, romance will continue to be the most loved and profitable genre in 2021 too, as readers tend to remain loyal to their favorite authors within the romance category. Popular romance subgenres include inspirational romance, romantic suspense, young adult, contemporary romance, and historical romance.


Many popular mystery books attract a large number of readers, standalone and series alike. The structure of the mystery novels is basically simple: they start with an exciting hook, keep the audience interested and engaged with specific suspenseful pacing, and draw a conclusion that answers all the readers’ questions.

As mystery books can be easily adapted into Netflix films and series, graphic novels, comic books, games, and interactive stories with reading apps, they get great help in becoming one of the best book genres. The best-selling mystery subgenres include cozy mysteries, police procedurals, true crime novels, hardboiled detective stories, and scientific mysteries.

Due to their speculative literary character, thriller and horror genres usually overlap with mystery and fantasy. Both categories are read throughout the year because people are always obsessed with the paranormal/supernatural and the dark side of human life.

Fantasy and Science Fiction

Despite their differences, book genres fantasy and science fiction (sci-fi) are closely related in multiple ways. Both genres tend to have an extensive number of imaginary and creative elements, and both are considered speculative fiction.

Even if many sci-fi stories can take place in a dystopian past, most of them are set in a frightening and insecure future and have to deal with unexpected events generated by the ramifications of scientific and technological development.

Fantasy subgenres include steampunk, urban and high fantasy, dark fantasy, epic fantasy, and sorcery and sword. At the same time, certain fiction genres like magical realism blend the pure attraction of fantasy with the challenging techniques found in literary fiction. And Gabriel Garcia Marquez’s One Hundred Years of Solitude is a good example of this idea.

Thriller and Horror

Authors like Dan Brown and David Baldacci dominate the list of best-selling thriller books, while Stephen King is recognized as a master of contemporary horror.

Young Adult

As young adult (YA) fiction brings popular adult genres into literature for teen audiences, these book genres will continue to sell like hotcakes in 2021. From sci-fi to romance, murder, or fantasy, the best books in the YA fiction genre include the same powerful stories and characters that are found in books for older readers. Often, themes for teenagers, such as adulthood or rebellion, overlap with existing literary tropes. J.K. Rowling was hugely successful in this niche with her Harry Potter series, as well as Suzanne Collins with The Hunger Games or R.L. Stine who through the series Goosebumps and Fear Street brings horror fiction to the audience of children and teenagers.

Best Themes for Book Genres In 2021

Pandemic: In the following years, the COVID-19 pandemic and the crisis generated by it will influence the works of many writers. Elements and themes such as global isolation, panic, natural disaster, socio-political disorders, and transformations caused by diseases and health crises, will appear in fiction and non-fiction books.

Dystopian: Usually a popular item of (social) fantasy and science fiction, dystopian elements will be used in many other book genres in the next years, including YA fiction. Due to the actual medical, social, economic, and political context, dystopian literature became very popular during the pandemic and for sure will inspire future works.

Artificial Intelligence (AI): Humanoid robots that also own human intelligence have always represented popular and catchy characters in sci-fi. Due to the development of robotics and AI, readers will see an increase in literary works dealing with artificial intelligence that takes different forms.

Women: Even if they have been a trend for a while now, female writers will continue to take the publishing world by storm. There are already published many works belonging both to the book genres nonfiction and fiction that present strong and independent female characters but also there are female writers who publish in sci-fi.

Bottom line

We don’t suggest you decide to write a romance novel just because it’s the most popular book category. The best option is to write the book you want to write and will best represent you. But it’s also important to know where your fiction might fit into the marketplace. Knowing which book genres are popular will help you to make the right decisions about who your readers might be and the channels you might end up using for distribution and promotion.