Password Strength Checker — free online tool
Estimate strength from length, character variety, and common patterns entirely in your browser—before you save a new master password. Nothing is sent to breach APIs.
When to use Password Strength Checker
Score a candidate password’s length and patterns locally before you save it in a manager.
Useful when you want a quick answer without pasting sensitive data into random chat bots.
What Password Strength Checker does not do
Local entropy/pattern hints only. No HIBP breach lookup and no “hack this password” service.
How to use Password Strength Checker
- Type a password into Password Strength Checker (use a test password, not a real one you rely on).
- Read entropy estimate and checklist feedback on the card.
- Optionally run the breach check if enabled—it sends only a hash prefix.
- Clear the field after testing; do not leave production passwords in the tab.
Practical tips
- Test a throwaway password with the same length and symbol mix as your real one before adopting it.
- Run the optional breach check only after you are comfortable with the hash-prefix (k-anonymity) method.
- Pair with the Password Generator when you need a fresh random string, then score it here.
Example
Type a 16-character test passphrase and read the local strength verdict.
Related tools on Webtoolshop
- Password Generator — Create a long random password, then score it here before you save it.
- Hash Generator — Generate SHA-256 or other digests for developer workflows—not for storing passwords.
Limitations
Heuristic score only. A “strong” label is not a guarantee against targeted attacks.
Privacy & data
We do not run a database on this static site. Text and generated output exist only in your tab until you close or refresh the page.
Frequently asked questions about Password Strength Checker
Is it safe to type my real password into Password Strength Checker?
The estimate runs locally in your browser and is never uploaded to Webtoolshop. Still, you can type a similar test password if you prefer, then apply the same length and character rules to your real one offline.
Does this page check Have I Been Pwned?
No. We removed third-party breach lookups so your password never leaves the device. Strength is based on length, variety, and common patterns only.
Does Webtoolshop store text I paste into the Password Strength Checker?
We do not run a database on this static site. Text and generated output exist only in your tab until you close or refresh the page.
Password Strength Checker
Length & character-set estimate — optional Have I Been Pwned check (SHA-1 prefix only).