Biggest Differences Between ‘The Summer I Turned Pretty’ TV Series and Books

The Summer I Turned Pretty has won over Prime Video viewers — but how does the TV adaptation compare to the original book series? The TV show, which premiered in July 2022, is based on the book series of the same name written by Jenny Han. The Summer I Turned Pretty follows Belly Conklin's (Lola Tung) relationships with childhood friends Conrad Fisher (Christopher Briney) and Jeremiah Fisher (Gavin Casalegno) and how their bond shifts as she explores her feelings for each of them. Han, who is the creator and showrunner of The Summer I Turned Pretty series, surprised fans when she hinted that her original vision for the story may change on screen. "I really had to weigh what the fans are expecting with where the show is going creatively and find that balance," she told Variety in June 2022. "My priority has always been that I want fans of the book to feel really satisfied by the story we’re telling, but also for them to know that this is an adaptation in a new medium, so it’s not going to be exactly the same. I think those are sort of the two things that are always in my head. I don’t want to spoil too much but the books have been out for a while. You never know what could happen with the show. I was open minded going into it. I was considering a lot of different possibilities." Meanwhile, Casalegno showed his support for a shakeup to the outcome of the central love triangle. "I do feel like there's a strong chance that that's a possibility," the actor exclusively told Us Weekly in June 2023 about the popular series potentially straying from the original events in the books. "Obviously, I know where [my character Jeremiah] ends up going and what ends up happening. But I don't emphasize on that. Because I think Jenny writes it so well that I'm able to kind of get there naturally without having to force it a certain direction." Before the third season premiered in July 2025, Han hinted at possible changes. "There are a couple of moments that people really love from the books that I knew that people were wanting to see," she told People at the time while noting that book moments "might not always happen in the way that you're expecting." "I wanted to make sure that I was going to really service those fans who've been following the story for a really long time," she added. Scroll on to see the main differences which had taken place on the show compared to the books so far:

During season 1, Susannah (Rachel Blanchard) convinces Belly to take part in the country club's debutante ball at Cousins Beach. The formal event sets the scene for the finale — and helps bring Belly and Conrad closer after months of build-up. In the book series, however, the ball was never mentioned. 

The Prime Video series doesn't utilize flashbacks as often as The Summer I Turned Pretty book would when it came to Belly's childhood.  

The youngest Fisher brother only showed interest in girls throughout the three books. On screen, meanwhile, Jeremiah has stated that his sexuality is more fluid and has flirted with various guys during the first season.

"I think it's so cool that Jenny is just sensitive to that [topic]. And I think that she really tries to incorporate today's world into the series," Casalegno exclusively told Us in June 2023. "So it's heartwarming because I feel like more people can relate [to the character]."

During the first season of the show, The Summer I Turned Pretty makes it a point to accentuate the importance of Conrad's gift to Belly for her 16th birthday. He initially claims he didn't buy her anything, but she later finds the necklace — which will continue to play a pivotal role in future seasons.

The books, however, didn't mention the jewelry until the sequel, It's Not Summer Without You.

In the first book, Belly's best friend Taylor (Rain Spencer) is only mentioned in flashbacks. The series, meanwhile, took the opportunity to explore Belly and Taylor's friendship more by having her pal visit Cousins Beach. The duo briefly has a falling out after Taylor kisses Belly's brother Steven (Sean Kaufman) but they work out their issues before the end of season 1. 

(Taylor and Steven's connection is another onscreen addition in season 1 which wasn't originally in the books.)

Belly's brother wasn't as pivotal to the book series, but that changed when the content was adapted for Prime Video. Steven has a major story line in season 1 as he tries to woo Shayla (Minnie Mills) even though they come from different financial backgrounds.

In the first book, Steven doesn't stay at Cousins for the whole summer because he is busy looking at potential colleges. Season 2 of the show expanded his role even more when it came to Steven's ups and downs with Taylor.

The Summer I Turned Pretty centers around the bond between the Conklins and the Fishers. Susannah's cancer isn't a secret to the two families in the book series, but the TV show tells a different story. Laurel (Jackie Chung) is originally the only one who knows about her best friend's health battle while Conrad secretly deals with the news after accidentally finding out.

In season 1, Susannah is ultimately forced to tell everyone when Jeremiah discovers emails about potential treatment.

In the aftermath of Susannah's cancer reveal, Belly and Conrad seemingly start a relationship as season 1 comes to an end. Conrad finally tells Belly about his feelings for her, which seemingly allows for the love triangle to work itself out.

The events in the books leave the Belly and Conrad vs Belly and Jeremiah debate more up in the air. Although Belly shares a kiss with her crush at the end of the first novel, it isn't clear whether they will be together after Conrad shuts down a potential romance between them.

In the second book, Belly and Conrad visit Cousins during the winter for a romantic date — but aren't intimate. The series, however, deviated from the source material by revealing that the couple had sex on the secret trip. Season 3 pushed that further by showing an extra sex scene between Belly and Conrad. 

Conrad escapes to his mother's summer home in the books after he finds out that his father will be selling the property. In season 2 of the show, viewers are introduced to new characters such as Susannah's sister, Julia (Kyra Sedgwick), and her child, Skye (Elsie Fisher), who help push that story line forward.

Since Skye wasn't featured in the original book series, their romance with Cam was a surprise for viewers. Skye and Cam shared a kiss in a season 2 episode after forming a connection during the summer.   

During season 2, Belly and Jeremiah’s kiss is seen by Conrad, which is inspired by the book series. The change, however, includes Belly wearing Conrad's Brown sweatshirt instead of the infinity necklace that he gave to her as a gift. 

The updates continued in the season 2 finale when Jeremiah told Belly to follow Conrad after she was the one to take the first step in the books. Belly and Jeremiah's relationship concluded the season but viewers also got a glimpse at Conrad's state of mind more as well.

In the book, Jeremiah only cheated on Belly once and he proposed in an effort to save their relationship. The show, meanwhile, confirmed that Jeremiah and Belly were sexually active by the time he cheated with Lacie and he popped the question after Steven's accident, which wasn't in the book.

Season 3 opted to limit some of the inner monologue viewers usually got from Belly. 

Similar to Han's book, season 3 showed Belly and Jeremiah officially ending their relationship. But We'll Always Have Summer didn't reveal anything between the events of Belly and Jeremiah's almost-wedding day and the epilogue several years later as Belly prepares to get married again.

In the book, Belly gives a general overview of what happened between those two days, but the show went a different direction. The last few minutes of episode 8 showed Belly packing up her things and leaving Cousins now that she had no future with Jeremiah.

She was then seen at the airport buying a ticket for Paris — where she was ultimately meant to go during next semester. But before she got on the plane, Belly saw Conrad waiting for his plane back to Boston, which near happened on the page.