Maximum length for MySQL TEXT field types
MySQL supports 4 TEXT field types,
MyISAM tables in MySQL have a maximum size of a row of 65,535 bytes, so all the data in a row must fit within that limit. However, the TEXT types are stored outside the table itself and only contribute 9 to 12 bytes towards that limit.
TEXT data types are also able to store much more data than VARCHAR and CHAR text types so TEXT types are what you need to use when storing web page or similar content in a database.
The maximum amount of data that can be stored in each data type is as follows:
TINYTEXT 256 bytes
TEXT 65,535 bytes(64kb)
MEDIUMTEXT 16,777,215 bytes(16MB)
BIGTEXT 4,294,967,295 bytes(4GB)
In most circumstances the TEXT type is probably sufficient, but if you are coding a content management system it's probably best to use the MEDIUMTEXT type for longer pages to ensure there are no issues with data size limits.