パスワードの強度を確認する — エントロピーとクラック時間

Type a password and see its entropy, estimated crack time, and exactly what to improve. Your password never leaves your device.

パスワードの強度をチェックする理由は何ですか?

Data breaches expose millions of passwords every year. Weak passwords are cracked in seconds. Reused passwords let attackers access multiple accounts. Knowing your password's real strength — not just what a website's colored bar says — is the first step to better security.

強度はどのように計算されますか?

The tool calculates entropy in bits based on password length and character diversity (lowercase, uppercase, numbers, symbols). It then estimates crack time assuming a high-end attacker with a trillion guesses per second. This gives you a realistic picture of how long your password would survive a targeted attack.

実際のパスワードを入力しても安全ですか?

Yes. The analysis runs entirely in your browser. No password is sent to any server, logged, or stored. For extra caution, you can type a password with the same length and character types as your real one — the entropy and crack time will be identical.

ブラウザベースのユーティリティ ツールを使用する理由は何ですか?

Online utilities like password generators, text formatters, and URL cleaners are convenient, but most send your data to remote servers. Our browser-based tools process everything locally — your passwords, text, and URLs never leave your device.

This is especially important for sensitive operations like generating passwords, checking password strength, or cleaning URLs that contain tracking parameters. With Presend, you get the convenience of online tools with the security of offline software.

当社のユーティリティツールがあなたのプライバシーをどのように保護するか

1. All processing happens in your browser using JavaScript
2. No data is transmitted to external servers
3. No cookies or tracking scripts monitor your usage
4. Your input data is cleared when you close the tab

当社のユーティリティ ツールを使用すると何ができるでしょうか?

Generate cryptographically secure passwords, check password strength against entropy analysis, convert between JSON and CSV formats, compare text differences, split long text into social media threads, clean tracking parameters from URLs, validate email lists, check color contrast for accessibility, and convert images to Base64 for embedding.

これらのツールは本当に無料ですか?

Yes — all our utility tools are completely free to use, with no registration required, no usage limits, and no watermarks. We believe privacy tools should be accessible to everyone, not locked behind paywalls or subscription models.