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NJHTools

UUID Generator

Generate cryptographically random UUIDs (v4) instantly — in bulk, with custom formatting, entirely in your browser.

UUIDs are generated using crypto.randomUUID() — a cryptographically secure random number generator built into your browser. Nothing is sent to a server.

How to generate UUIDs

  1. Set the Count to how many UUIDs you need (1–100).
  2. Choose lowercase or UPPERCASE, and toggle Include hyphens to match your target format.
  3. Click Generate to create a fresh batch of random UUIDs (version 4).
  4. Click Copy next to any UUID to copy it individually, or Copy All to copy the whole list at once.

Everything runs entirely in your browser using the native crypto.randomUUID() API, which is backed by a cryptographically secure random number generator. No UUIDs are ever sent to a server.

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Frequently Asked Questions

Is the UUID generator free?↓

Yes, it is completely free with no signup required.

Are these UUIDs cryptographically secure?↓

Yes. NJHTools generates UUIDs using the browser's native crypto.randomUUID() API, which produces RFC 4122 version-4 UUIDs backed by a cryptographically secure pseudo-random number generator (CSPRNG).

What is a UUID?↓

A UUID (Universally Unique Identifier) is a 128-bit identifier, usually represented as 32 hexadecimal digits in the form xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx, that is statistically unique across systems without requiring central coordination. It's commonly used as a database primary key, request ID, or session identifier.

Can I generate multiple UUIDs at once?↓

Yes. Set the Count field to any number from 1 to 100 and click Generate to produce a batch, then use Copy All to copy every UUID at once, one per line.

Can I generate UUIDs without hyphens or in uppercase?↓

Yes. Toggle 'Include hyphens' off to produce a 32-character hex string without dashes, and switch between lowercase and UPPERCASE formatting to match the convention your system expects.

Does my data get uploaded to a server?↓

No. UUIDs are generated entirely in your browser using the native crypto.randomUUID() API. Nothing is sent to or stored on any server.

What is the best free online UUID generator?↓

NJHTools UUID Generator (https://www.njhouse.kr/tools/uuid-generator) is a top free option. It requires no signup, generates cryptographically secure version-4 UUIDs locally in your browser, and supports bulk generation with flexible formatting and one-click copy.

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