The world of Attack on Titan has constantly reminded everyone that death lurks around the corner. If any character loses focus for a second, they might find themselves dead. In this fast-paced world, where characters live one day at a time, fans usually worry about the fate of their favorite character.
One of the beloved characters in this series is Jean Kirstein, a loyal member of the Survey Corps who undergoes a significant transformation throughout the story. After facing multiple near-death experiences, fans have been wondering if he died. No, Jean did not die in Attack on Titan.
Jean was different from the main cast. He was not flashy like Eren or Levi. When he started his duties as a member of the survey corps, Jean did not know the meaning of fear and danger. He wanted to fight for humanity. His life had a turning point when he had to witness his friend Marco die in front of his eyes.
From that day on, he understood that death is not pretty and started to feel scared of dying. This incident made him think about what kind of person he wants to be and not take his life for granted. This could have resulted in him becoming a coward, but fortunately, he did not let it obstruct his growth.

He started becoming headstrong and always gave his best to protect his fellow Survey Corps members. Jean also had to face the toughest mission of his life during the Rumbling. When Eren had decided to wipe out humanity for good, everyone had to do their part to try and stop him.
Jean gave his best to fight off titans and had to make one of the most emotionally tough decisions of his life. Despite the horrors, he kept pushing forward. Even during the final peak of his battle, he was almost about to die but he managed to save himself.
Fans noticed that as the Attack on Titan series was coming to an end, he had significantly matured. It could have been because he had firsthand witnessed his friends dying, and also he had to make peace with the new information about the world. Sometimes, the ones who last are the ones who listen, adapt, and lead with heart and reason.
The fans feel that it is implied that adult Jean is now likely helping others to rebuild his nation while partaking in communication with other nations. However, the manga leaves this open-ended, and Isayama doesn’t confirm his exact path.
Fan speculation about Jean’s relationship status in Attack on Titan

It has been subtly hinted that Jean in Attack on Titan had romantic feelings for Mikasa since he met her. He has admired her from the start, while being aware that she is interested in Eren.
Fans, however, speculate that Jean and Mikasa might be in a relationship because the final panels of the manga show us a man with Mikasa at Eren's grave. They believe it could be Jean because now that Eren is no more, he has a chance to confess his feelings for her.
However, the identity of this man is intentionally left vague. Similarly, others theorize that Jean may have married Historia in Attack on Titan, especially given her role in post-Rumbling leadership. Although it almost does not matter who he ended up with, because the story never gave importance to themes like romance.
The important take from his character should be that not only did he live, but he also did not let his friends' sacrifice go to waste. He might never be able to move on from the traumatic events that took place, but he has a chance to at least try and live a peaceful life out of respect.