Free UUID Generator Online (v4)
Generate up to 100 cryptographically random UUID v4 identifiers instantly. Uppercase and no-hyphen options. Browser-only, no signup.
A UUID generator creates Universally Unique Identifiers — 128-bit values formatted as 32 hex digits in the 8-4-4-4-12 pattern. Notepad AI's generator produces UUID v4 (fully random) using the browser-native crypto.randomUUID() API. Generate up to 100 at once, never uploaded.
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UUID Generator FAQ
What is a UUID?
A UUID (Universally Unique Identifier), also called a GUID, is a 128-bit identifier formatted as 32 hexadecimal digits in five groups separated by hyphens (8-4-4-4-12). UUID v4 — the type this tool generates — is randomly generated, making collisions astronomically unlikely (you'd need to generate billions per second for decades to risk one).
Is the UUID generator free?
Yes — completely free, no signup, no login. Generate up to 100 UUIDs at once, as many times as you like.
Are these UUIDs cryptographically secure?
Yes. The generator uses the browser-native crypto.randomUUID() API (with a crypto.getRandomValues fallback), which provides cryptographically strong randomness. UUIDs are never sent to any server.
What's the difference between UUID v4 and other versions?
UUID v4 is fully random. v1 is time-and-MAC-address-based (can leak info). v3/v5 are hash-based (deterministic from a name). v4 is the most common for general use because it's random and requires no input.
Can I generate UUIDs without hyphens?
Yes — toggle 'Include hyphens' off to get a 32-character hex string with no dashes. Useful for database keys or URL slugs where hyphens are inconvenient.
Is my data private?
Yes. All UUID generation happens in your browser using built-in crypto APIs. Nothing is uploaded, logged, or tracked.
What are UUIDs used for?
Database primary keys, distributed system identifiers, API request IDs, session tokens, file names that must not collide, and anywhere you need a unique identifier without a central coordinator handing out sequential IDs.