Length matters more than complexity. A 20-character lowercase-only password (95 bits) is stronger than a 10-character mixed-type password (66 bits). Always maximize length first, then add character diversity. The entropy score tells you the real strength — aim for 72+ bits for general accounts and 100+ bits for critical accounts.
The strength meter provides a quick visual indicator, but the entropy number is more precise. Two passwords with the same character types but different lengths will have very different entropy scores. A password rated Strong with 80+ bits is sufficient for most accounts; Very Strong (100+ bits) is ideal for your password manager master password.
Use this generator in conjunction with a password manager. Generate unique passwords for every account, store them all in your manager, and never reuse passwords. The small effort of setting up a password manager pays enormous dividends in security.