Strong random passwords with strength meter — 100% free, runs in your browser
Passwords people invent themselves follow patterns that cracking software knows well — a name, a year, an exclamation mark. Random generation avoids that entirely. Length protects you more than complexity does, so a longer password with fewer symbol types still beats a short cryptic one.
Sixteen characters is a sensible minimum for important accounts. Every extra character multiplies the effort needed to crack it.
Yes. It uses your browser's cryptographic random source, not the ordinary random function, which is predictable enough to matter here.
This one never leaves your browser and is not transmitted or stored. Still, for your most critical accounts, a dedicated password manager is the better habit.
No. Reuse is how one leaked site becomes a compromise of every account you own.