Password Strength Checker

Password Strength Checker estimates resistance to guessing with zxcvbn-ts, a pattern-aware engine that recognizes common passwords, dictionary words, names, dates, repeated blocks, sequences, keyboard paths, and predictable substitutions. Length helps most when it comes from unrelated words or generated randomness; adding one capital letter, number, or symbol to a common word rarely provides the same benefit.

1. 1.Enter a proposed password. Local analysis begins after a short pause.
2. 2.Review the strength result, primary issue, and prioritized recommendations.
3. 3.Inspect masked patterns and compare the four illustrative attack scenarios.
4. 4.Optionally check known breach exposure. Only a five-character SHA-1 prefix is sent to the range service.
5. 5.Copy or export a redacted report that excludes the password, hash, matched text, and context values.

Strength is an estimate, not a guarantee or a compliance verdict. Crack times vary with the stolen hash, hashing algorithm, work factor, hardware, rate limiting, and attacker strategy. A password found in breach data should be replaced completely even when its estimated strength is high, and every account should use a unique password. A password manager is the safest practical way to generate and store unique passwords.

The raw password and optional context remain in browser memory: they are not persisted, added to the URL, logged, analyzed, or included in exports. Breach checking is explicit and uses a k-anonymity range lookup; not found does not prove a password has never been exposed. JavaScript cannot guarantee immediate cryptographic memory erasure, so avoid testing a real production password on any website if that exceeds your risk tolerance.