無料パスワード強度チェッカー

あなたのパスワードは十分に強力ですか？

データ侵害の80%は弱いまたは盗まれたパスワードが関与しています。. 下にパスワードを入力して、その安全性を確認してください。私たちのチェッカーは、長さ、複雑さを分析し、既知の一般的なパスワードと比較します — すべてブラウザを離れることなく行われます。.

How to read your result

The score reflects three things: length, unpredictability, and whether the password appears in lists of commonly breached passwords. A short password with symbols (like P@ss1!) scores worse than a long, plain passphrase, because attackers crack length last. If the checker flags your password, the fix is usually not “add another symbol”, it is “make it longer and less predictable”. Aim for something a stranger could not guess even if they knew you.

What actually makes a password strong in 2026

• Length beats complexity. Aim for at least 16 characters. A four-word passphrase is both stronger and easier to remember than a short scrambled string.
• Unique per account. Reuse is what turns one breach into ten. If a checked password is one you use elsewhere, change it everywhere.
• Let a manager do the work. Generate and store passwords in a password manager so you never have to memorise or reuse them. Create fresh ones with our secure password generator.

Everything runs in your browser, but as a habit, avoid pasting a password you actively use into any online field. Test a similar pattern instead. For the bigger picture, see how to tell if a software is real or fake and browse all our free security tools.

よくある質問

Is it safe to type my password here?

The check runs in your browser and the password is not sent anywhere. Even so, the safest habit is to never type a password you actively use into any online tool. Test a similar length and pattern instead.

How long should my password be?

At least 16 characters. A longer passphrase of several unrelated words is stronger than a short string full of symbols, and far easier to remember.