macOS Sonoma is available today
Not all can be upgraded to Sonoma. These pages help identify your Mac model and the newest compatible operating system it can be upgraded to:MacBook Pro https://support.apple.com/en-us/HT201300MacBook Air https://support.apple.com/en-us/HT201862iMac/iMac Pro https://support.apple.com/en-us/HT201634Mac Pro https://support.apple.com/en-us/HT202888Mac Studio https://www.apple.com/mac-studio/Mac Mini https://support.apple.com/en-us/HT201894