Are these passwords truly random?

Yes. They use the Web Crypto API's getRandomValues, which provides cryptographically secure random numbers suitable for generating high-entropy secrets.

What length should I use?

At least 16 characters for general use, 20+ for high-security accounts. Each additional character multiplies the search space by the alphabet size.

Which character types should I include?

Include uppercase, lowercase, numbers, and symbols for maximum entropy. Some sites reject symbols; in that case, use a longer alphanumeric password.

What does 'exclude similar characters' do?

It removes visually confusable characters: l, 1, I, O, 0. Useful when passwords must be read or typed manually.

Is the generated password stored anywhere?

No. The password exists only in your browser memory. It is not saved to localStorage, history, or sent to any server. Copy it to your password manager immediately.

Why was my generated password rejected by a website?

Some sites restrict certain symbols or length. Check the site's password policy and adjust the character types or length accordingly, then regenerate.

パスワードジェネレーター

Generate strong, cryptographically secure random passwords。無料、プライベート、100%クライアントサイド。

param.lengthparam.uppercaseparam.lowercaseparam.numbersparam.symbolsparam.excludeSimilarparam.minEachType

入力

例を試す:

出力

Local only

使い方

Set the desired password length.
Toggle character types: uppercase, lowercase, numbers, symbols.
Optionally exclude similar characters (l, 1, I, O, 0).
Copy the generated password.

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暗号学的に安全なランダムパスワードを生成する

暗号学的に安全な乱数ジェネレーターを使い、長さと文字種を制御して高エントロピーのパスワードを作成します。

タスク

暗号学的に安全な擬似乱数生成器を使う

CSPRNG は真の乱数と区別がつかない出力を生成します。正しい API と、セキュリティ文脈で Math.random() が禁止される理由を学びましょう。

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よくある質問

Are these passwords truly random?: Yes. They use the Web Crypto API's getRandomValues, which provides cryptographically secure random numbers suitable for generating high-entropy secrets.
What length should I use?: At least 16 characters for general use, 20+ for high-security accounts. Each additional character multiplies the search space by the alphabet size.
Which character types should I include?: Include uppercase, lowercase, numbers, and symbols for maximum entropy. Some sites reject symbols; in that case, use a longer alphanumeric password.
'exclude similar characters' は何をしますか？: It removes visually confusable characters: l, 1, I, O, 0. Useful when passwords must be read or typed manually.
Is the generated password stored anywhere?: No. The password exists only in your browser memory. It is not saved to localStorage, history, or sent to any server. Copy it to your password manager immediately.
Why was my generated password rejected by a website?: Some sites restrict certain symbols or length. Check the site's password policy and adjust the character types or length accordingly, then regenerate.

パスワードジェネレーター

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よくある質問

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