18-Character Password Generator

Yes, with a wide margin. A random 18-character password using all four character types has about 116 bits of entropy, well beyond brute-force range for any current or foreseeable hardware. At this length the realistic threats are phishing, malware, and password reuse — not guessing.

An offline attacker testing 10 billion guesses per second would need about 1.3 × 10¹⁷ years on average — more than ten million times the age of the universe. That figure assumes the password is truly random; an invented 18-character phrase can fall far faster to dictionary and pattern attacks.

Policies that step above NIST’s recommended 15-character minimum often pick 18 or 20 for higher-trust tiers — DigiCert’s CertCentral, for example, offers 12, 15, 18, and 20 characters as minimum-length settings. Eighteen gives a clear buffer over the baseline without approaching the caps some older systems impose.

Two extra random characters add about 13 bits and multiply the keyspace by 7,744 (88 × 88). Both lengths are already beyond brute force, so the gain is margin rather than a change in category — worth having when a policy asks for 18, harmless when it does not.

They help but are not essential. With symbols a random 18-character password reaches about 116 bits; with letters and numbers only, about 107 bits. Both are far past brute-force reach, so drop symbols without worry where a form rejects them.

Not reliably if it is truly random — and you should not need to. Store it in a password manager. For the few secrets you must type from memory, such as the manager’s master password, a passphrase of six or more random words is far easier to remember and still beyond practical attack.