What is the longest stay of Schengen individual tourist visa?

The Schengen visa is valid for 90 days.

The Schengen agreement countries decided to issue a unified visa that is generally valid in the Schengen area; A short-term travel visa that allows one or two entry, provided that the total number of days of stay within six months after the first entry cannot exceed three months; According to the provisions of the Schengen Agreement, travelers with valid residence permits of any member country of the Schengen Agreement can travel freely in the Schengen area without a visa within three months. Passengers outside the Schengen area can travel to Schengen countries without a visa as long as they have a valid residence permit and passport. If the stay exceeds 90 days, the applicant should apply for a national visa according to the relevant laws and the purpose of stay.