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UUID Generator

Generate RFC 4122 v4 UUIDs in bulk with the browser crypto API.

Runs locally in your browser — no upload.

Free Online UUID Generator

Universally unique identifiers are the backbone of modern systems: primary keys, API request IDs, file names, session tokens, distributed event tracing. When two machines must create identifiers that will never collide without talking to each other, UUID version 4 is the answer — 122 bits of cryptographic randomness formatted as the familiar eight-four-four-four-twelve string.

This generator produces v4 UUIDs straight from your browser's Web Crypto API — the same cryptographically secure source browsers use for keys and nonces, not a predictable pseudo-random sequence. Need one identifier or a hundred? Set the batch count and generate instantly, then copy entries individually or grab the whole list newline-separated for spreadsheets, seed files or test fixtures. Every generated value is validated against the RFC 4122 layout (version nibble 4, variant bits 10x) so you always receive canonical output.

Generation happens entirely offline: nothing is requested, recorded or logged, which makes the tool safe for producing identifiers destined for production systems. It works identically on desktop and mobile browsers, with or without an internet connection.

How to Use This Tool

  1. Set the count — enter how many UUIDs you need (1–100 per batch).
  2. Generate — click once and the list appears immediately.
  3. Copy — use the icon beside any single UUID, or Copy all for the full batch separated by newlines.
  4. Regenerate — need a fresh set? One click replaces the entire list.

Benefits

  • Cryptographically random — powered by crypto.randomUUID / getRandomValues, never Math.random.
  • Bulk batches — up to 100 UUIDs at once with copy-all support.
  • Canonical format — lowercase, hyphenated, RFC 4122 compliant.
  • Works offline — fully local generation with zero data collection.
  • Free forever — unlimited batches, no signup.

Frequently Asked Questions

A UUID (Universally Unique Identifier) is a 128-bit identifier formatted as 36 characters — 32 hexadecimal digits in five groups, like 3f8a2c1e-9b4d-4c7a-8d2f-1a5b9e7c3d40. Version 4 UUIDs are generated from random data, giving roughly 122 random bits, which makes accidental collisions practically impossible.

They are produced by your browser's built-in cryptographic random number generator (crypto.randomUUID, with a crypto.getRandomValues fallback). This is the same source browsers use for security-sensitive operations, not a predictable pseudo-random sequence.

You can — random UUIDs work across distributed systems without coordination. Be aware that completely random IDs can fragment B-tree indexes at very large scale; many teams therefore prefer UUIDv7 or ULID for hot database paths while still using v4 for general identifiers like API keys and request IDs.

The canonical form is lowercase with hyphens, which is what this tool outputs. RFC 4122 says consumers should accept case-insensitive input and optional braces, but if a system demands a specific style you can transform after pasting.

Up to 100 per batch. Set the count, generate once, and copy entries individually or grab the whole list newline-separated — handy for seed files, test fixtures and spreadsheet imports.

No. Everything happens locally using the Web Crypto API, so batch generation works even offline, and no identifier is ever recorded anywhere.

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