┌ OneStop-CYworld ┐

Pass Strength & Breach Check

Instantly verify if a password appeared in public breaches using Have I Been Pwned's privacy-preserving range API. We never store or transmit your full password.

┌ Check password ┐
Estimated entropy0%

Tip: Use this for spot checks only. For stronger protection, switch to a password manager with breach monitoring.

┌ Result ┐

Ready to check

Use the k-anonymity lookup to see if your password surfaced in known breaches.

┌ How the k-anonymity check flows ┐
1

Local hashing

Your password never leaves the browser. We create a SHA-1 hash locally.

2

Prefix split

Only the first 5 characters of the hash are kept for the lookup.

3

HIBP query

We call Have I Been Pwned with the prefix using the k-anonymity range API.

4

Local comparison

We compare the returned hash suffixes locally against yours.

5

Exposure result

If a match is found, we report how many times the password appeared in breaches.

┌ Why it matters ┐

Have I Been Pwned maintains billions of breached passwords. By checking your password with k-anonymity, you learn if attackers have already seen it—without exposing the full password to any service, including us.

  • Rotate any password that appears in breaches and avoid reusing it across accounts.
  • Prefer passphrases or randomly generated passwords stored in a reputable manager.
  • Enable multi-factor authentication to mitigate damage even if a password leaks.