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ジェネレーター

ブラウザで QR、パスワード、UUID、Lorem Ipsum などを生成。

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ジェネレーター

Why browser-only generators?

Most online generators send your configuration and output to a server for logging, analytics, or resale. That is especially problematic for security-sensitive tools: if a server logs every password you generate, those passwords are no longer private. The generators on this page use the Web Crypto API (crypto.getRandomValues) directly in your browser — the same cryptographically secure source that powers TLS and password managers. No requests leave your device; nothing is stored or logged.

The same reasoning applies to fake test data. Phone numbers, addresses, and card numbers generated for testing should not be submitted to third-party services that might store or misuse them. Running everything locally eliminates that risk entirely.

Choosing the right generator

For account passwords, use the Password Generator when you need maximum entropy in a short string, or the Passphrase Generator when you need something memorable enough to type without a manager. For developer workflows, the UUID Batch Generator produces hundreds of v4 or v7 UUIDs ready for database seeding. The Fake Name Generator and Fake Card Generator cover user-profile and payment-flow test data without touching real personal information.

For design work, the Color Palette Generator produces harmonious palettes from a base hue using color theory rules, while the CSS Gradient Generator outputs ready-to-paste gradient CSS. The Lorem Ipsum Generator fills text containers with realistic placeholder copy — including Chinese placeholder text for multilingual mockups.

よくある質問

Are the generated passwords and UUIDs truly random?
Yes. All generators use the Web Crypto API (crypto.getRandomValues), which is cryptographically secure and available in every modern browser. Passwords and UUIDs are not predictable from prior outputs.
Is any generated data sent to a server?
No. Every generator runs entirely in your browser. Nothing leaves your device — not passwords, not UUIDs, not fake names, not card numbers. There is no server and no logging.
Can I use the fake credit card numbers for real purchases?
No. The fake card numbers pass the Luhn checksum algorithm used for format validation, but they are not linked to any real account and will be declined by every payment processor. They are intended solely for software testing.
What is the difference between a password and a passphrase?
A password is a short string of mixed characters (letters, digits, symbols). A passphrase is several random words joined by a separator — longer, but easier to remember and type. A 5-word passphrase typically has more entropy than a 12-character random password.
Which UUID version should I use — v4 or v7?
Use UUID v4 for general-purpose unique IDs when order does not matter. Use UUID v7 when you need lexicographic sort order aligned with creation time — ideal for database primary keys that benefit from clustering.
Do the color palette and gradient generators work offline?
Yes. All tools are static pages with no external dependencies loaded at runtime. Once the page is loaded, they work without a network connection.
Can I download the generated output?
The UUID Batch Generator and Fake Name Generator support CSV download. Other tools offer clipboard copy. If you need a specific export format, open a GitHub issue.
Are these tools mobile-friendly?
Yes. Every generator is designed mobile-first with large touch targets and responsive layouts. They work in Safari, Chrome, and Firefox on iOS and Android.
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