Lan Wangji is older than Wei Wuxian.
- Lan Wangji was born in 1301, while Wei Wuxian was born in 1305.
- This means Lan Wangji is four years older than Wei Wuxian.
- Their age difference is a significant factor in their relationship, as Lan Wangji often acts as a more mature and responsible figure to Wei Wuxian.