パスワードジェネレーター
カスタムルールで安全なランダムパスワードを生成します。
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Creating Strong, Random Passwords
概要
A strong password is long, random, and unique to each account — qualities humans are bad at inventing but a generator handles instantly. This tool builds passwords from letters, numbers, and symbols entirely in your browser, so the password is never sent over the network.
使い方（ステップ）
- 1
Set the length
Aim for at least 16 characters; longer is stronger.
- 2
Choose character types
Enable uppercase, lowercase, numbers, and symbols for maximum strength.
- 3
Copy and store it
Generate, copy the password, and save it in a password manager rather than reusing it.
仕組み
The generator uses the browser's cryptographically secure randomness to pick characters from the sets you enable (uppercase, lowercase, digits, symbols). Length and character variety together determine entropy — the measure of how hard a password is to guess. Each extra character and each enabled set multiplies the number of possible combinations, making brute-force attacks exponentially harder.
こんなときに使う
Creating a unique password for a new account. Replacing a weak or reused password flagged in a breach. Generating credentials for a database, API, or service that needs a strong secret.
よくある質問
At least 12 characters, and 16 or more for important accounts. Length matters more than complexity for resisting brute-force attacks.