https://www.mysqltutorial.org/mysql-basics/mysql-varchar/

MySQL VARCHAR is the variable-length string whose length can be up to 65,535. MySQL stores a VARCHAR value as a 1-byte or 2-byte length prefix plus actual data.

The maximum length, however, is subject to the maximum row size (65,535 bytes) and the character set used. It means that the total length of all columns should be less than 65,535 bytes.