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Wachtwoord Lek Checker — Gratis online tool

Controleer of je wachtwoord in een datalek zit

Check of je wachtwoord gelekt is in een datalek. Via HaveIBeenPwned k-anonymity API — je wachtwoord verlaat nooit je browser. Gratis.

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Your password stays on your device
We use k-anonymity: only the first 5 chars of your password's SHA-1 hash are sent to HaveIBeenPwned. Neither they nor we ever see your full password.
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Meer weten

Free password breach checker — HaveIBeenPwned integration

Check if your password has been leaked in a data breach. Uses HaveIBeenPwned\'s k-anonymity API — your password never leaves your device. Database contains 850M+ leaked passwords from real breaches.

How to use this tool

  1. 1

    Type your password

    Enter the password you want to check. We hash it locally — only the first 5 characters of the hash ever leave your browser.

  2. 2

    Check against breach database

    We query HaveIBeenPwned's k-anonymity API — the world's largest leaked password database (850M+ breached passwords).

  3. 3

    If leaked: change immediately

    Any password showing as leaked = change it everywhere you use it. Leaked passwords are in attacker dictionaries.

What to do if your password is breached

  1. Change it immediately at every site where you use it
  2. Never reuse passwords across sites — use a password manager
  3. Enable 2FA on email, banking, social accounts
  4. Generate new passwords with our Password Generator (16+ chars, all categories)

Frequently Asked Questions

Is my password sent to anyone?
Nee — thanks to k-anonymity. We SHA-1 hash your password locally, send only the first 5 characters of the hash to HaveIBeenPwned's API. They return all hashes starting with those 5 chars. Your full hash (and password) never leave your device.
What is HaveIBeenPwned?
The largest public database of leaked passwords and accounts, maintained by security researcher Troy Hunt since 2013. Contains 850M+ passwords from real data breaches (LinkedIn, Adobe, Yahoo, etc.).
If my password isn't in the DB, is it safe?
Safer, but not guaranteed. New breaches happen daily. A "not leaked" result means it's not in known public breaches — doesn't prevent future leaks. Use unique passwords per site + password manager.
My password was leaked 100 times — meaning?
It appeared in 100 breach records. Common passwords like "123456" appear millions of times. Any number > 0 = attackers have this password in their dictionaries. Change it.
Why SHA-1 and not SHA-256?
HaveIBeenPwned uses SHA-1 for historical reasons. Despite SHA-1 being cryptographically weak, it's fine for this use — the password is still k-anonymous (5-char prefix = 1-in-1M lookup).
Can I test multiple passwords?
Yes, one at a time. We never log what you test. Each check is independent.

Belangrijkste punten

  • Password Breach Checker is a free, browser-based developer tool — check if your password has been in a data breach.
  • Nee signup, no downloads, no file uploads — your data stays on your device.
  • Works on desktop, tablet, and mobile. Install as a PWA for offline access.

How to Use Password Breach Checker

  1. Open the tool: Launch Password Breach Checker on Toololis — no account or download needed.
  2. Enter your data: Paste text, enter values, or select a file directly in your browser.
  3. Get instant results: Everything is processed locally — results appear immediately.
  4. Copy or download: Save your output or share it. Bookmark for quick access next time.

Password Breach Checker — Quick Facts

Prijs
Gratis — geen limieten, geen watermerk, geen paywall
Privacy
100% in de browser — geen data verlaat je apparaat
Platform
Elke moderne browser — desktop, tablet of mobiel
Categorie
Developer Tools on Toololis
Offline
Works offline after first visit (Progressive Web App)
FunctieDetails
ToolPassword Breach Checker
CategorieDeveloper
Aanmelden vereistNee
Bestand uploadenGeen — verwerkt in browser
Mobiel ondersteundVolledig responsive
KostenVoor altijd gratis

Why Use Password Breach Checker?

You should try Password Breach Checker for a quick, private way to check if your password has been in a data breach. All processing happens in your browser. Your files and data never leave your device. According to web.dev, client-side processing is the gold standard for privacy.

On the other hand, dedicated APIs or desktop tools suit batch processing better. They also handle server-side automation. For everyday tasks, browser tools offer the best speed, privacy, and convenience.

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100% Privacy. Deze tool draait volledig in je browser. Je gegevens worden nooit naar een server geüpload.