As one of the most popular Harry Potter characters and the only woman in the main trio, it would be understandable to think that there's nothing the audience doesn't know about Hermione Granger. Played by Emma Watson who made the role legendary, Hermione stands by her friends, fights alongside them, and goes on to have a successful career as well as children with Ron, whom she marries.
However, just like with most Harry Potter characters, the movie franchise also changed some things about Hermione. Some of the changes are fairly small and have no real impact on Hermione, but others change the character as well as what Hermione represents. In short, who she is as a person.
7 Ron Saves The Day, Not Hermione
Hermione is calm and composed for the most part in the movies thanks to her knowledge and intelligence, but not as much as the movies would like the audience to believe. In the first movie, there's a major difference while the trio is trying to reach for the Sorcerer's stone.
When they're caught by Devil's Snare, Hermione realizes what to do, that it's light that defeats the Devil's Snare. Ron, on the other hand, panics and almost dies because of it. However, the opposite happens in the books, where Ron saves the situation, not Hermione, who's too busy panicking at that moment.
6 Hermione Breaks Her Own Rules
In the third movie, Hermione uses the Time-Turner to visit all the classes she wants to. But even more importantly, she and Harry use it to save Sirius. Hermione points out to Harry that it's important not to interact with her past self in the slightest, as it presents a terrible risk.
Yet she later breaks her own rules when she throws a rock at Harry and gets a glimpse of herself in the forest. Nothing so dramatic happens in the book, where Hermione follows the rules and she and Harry manage to remain unnoticed by their younger selves.
5 Hermione Has A Different Ball Dress
It's a small detail but one that fans of the books noticed nonetheless. In the books, Hermione has a beautiful blue dress when she goes to the Triwizard Tournament's ball with Viktor Krum as her dance partner.
However, in the fourth movie, Hermione sports a pink dress instead. In both cases, though, she draws attention to her appearance, as she's much more styled and polished than usual when she attends the ball.
4 Hermione's Not A Prefect
Even though Hermione had her hands busy during her studies as she helped Harry fight Voldemort and other enemies, she still took the time to study hard. As a result, it was only natural she would become the new Prefect in her fifth year at Hogwarts. As for the other one, the honor went to Ron, which led to Harry's disappointment.
Mrs. Weasley, on the other hand, decides to celebrate the occasion because she's proud of Hermione's and Ron's achievements. The movie doesn't include Hermione becoming a Prefect, probably because it would have no major impact on the storyline, other than showing Harry's worsening mood.
3 Hermione's Dance With Harry
While the trio is searching for the Horcruxes, they aren't having such a good time. At one point, Ron leaves and Hermione is sad because of it. Harry cheers her up by dancing with her in their tent and having fun for a moment. The scene which warmed the heart of multiple movie fans isn't from the books.
However, it makes sense in the context of things since Harry is a good friend, one who would want to cheer Hermione up. The dance also fueled the wish many fans may have harbored that Hermione and Harry would end up together instead of her and Ron. But as the scene proves, they work just as well as friends, most likely even better.
2 Hermione's Too Beautiful
One of the aspects of the movies about Hermione that many fans of the books weren't happy about is that she's too beautiful. In the books, Hermione is far from ugly but she has unruly hair and large teeth, at least until she has them magically fixed. Emma Watson only had unruly hair in the first two movies and she never had large teeth.
The change in Hermione's movie appearance takes away attention from what the character is really about. Hermione values knowledge and education above physical beauty and it's difficult to imagine her styling her hair every morning before class.
1 Hermione Doesn't Start S.P.E.W.
Other than studying and helping her friends, Hermione also finds the time to start S.P.E.W. in the books. Hermione creates the organization named Society for the Promotion of Elfish Welfare when she sees how house-elves are abused by their owners.
However, not all house-elves are excited about Hermione's activities and seem to prefer their current way of life. The movies don't include S.P.E.W., most likely because it would draw the attention away from the main storyline.