How strong passwords work (length, entropy, and uniqueness)

A strong password resists guessing and cracking. Strength comes mainly from length, randomness, and uniqueness - not from swapping letters for symbols in a memorable word.

Length beats clever tricks

Each extra random character multiplies the search space. Aim for at least 16 characters on important accounts when the site allows it. A long random string stored in a password manager usually beats a short "clever" password you reuse.

Entropy and character sets

Mixing uppercase, lowercase, digits, and symbols increases entropy per character when the values are truly random. Predictable patterns (SeasonYear!, Name123!) add little strength even if they look complex.

Uniqueness per site

Reuse turns one breach into many. Credential stuffing succeeds because people recycle passwords. Generate a unique secret for each site and let a manager remember it.

Passphrases vs random strings

Both can be strong. Random high-entropy strings pair well with autofill. Memorable passphrases help when you must type by hand - still prefer length, unpredictability, and no personal details.

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