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Free UUID Generator

Generate UUIDs instantly, fully in-browser, no external services.

UUID Generator

What Is It?

The UUID Generator creates Universally Unique Identifiers (UUIDs) — 128-bit random values guaranteed to be unique across systems and time. UUIDs are a standard mechanism for generating primary keys, session tokens, correlation IDs, and file names without requiring a central authority.

All UUIDs are generated entirely within your browser using the native crypto.randomUUID() API, ensuring true cryptographic randomness and complete privacy.

How to Use

  1. Choose how many UUIDs to generate (default: 1).
  2. Click Generate to produce the UUIDs.
  3. Each UUID is displayed in standard hyphenated format (xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx).
  4. Click Copy All to copy the full list to your clipboard.

Example

Generated UUIDs:

f47ac10b-58cc-4372-a567-0e02b2c3d479
3b1e9d4a-2f8c-47a1-b5d9-1c3a4e8f2b7d
9a0c6e2f-4d1b-48c3-a7f5-6e9b0d3c2e1a

Benefits

  • Cryptographically secure — uses the browser’s built-in crypto.randomUUID(), not a mathematical pseudo-random function.
  • No server round-trip — no API call, no latency, no rate limiting.
  • Bulk generation — create multiple UUIDs in one click for batch operations.
  • Standard format — always outputs RFC 4122 v4 compliant UUIDs.

Common Use Cases

  • Generating primary keys for database records without auto-increment.
  • Creating unique session or request correlation IDs for distributed systems.
  • Producing unique file names to prevent collisions in storage buckets (S3, GCS).
  • Setting up test fixtures or seed data with deterministic-looking unique identifiers.
  • Generating idempotency keys for payment APIs and webhook systems.

Frequently Asked Questions

Are these UUIDs truly unique?

UUID v4 relies on 122 bits of cryptographic randomness. The probability of a collision is astronomically small — effectively zero for any practical application.

What UUID version does this generate?

This tool generates UUID v4 (random), which is the most universally supported and recommended version for general-purpose unique IDs.

Can I use these UUIDs as database primary keys?

Yes. UUID v4 is widely used as a primary key type in PostgreSQL, MySQL, MongoDB, and most other databases. Note that random UUIDs can fragment B-tree indexes over time — UUID v7 (time-ordered) is recommended for write-heavy tables, but falls outside the scope of this tool.

Is it safe to use UUIDs generated here in production?

Yes. The crypto.randomUUID() API uses a cryptographically secure pseudorandom number generator (CSPRNG), making these UUIDs suitable for production identifiers.

What’s the difference between a UUID and a GUID?

Nothing significant. GUID (Globally Unique Identifier) is Microsoft’s terminology for the same concept. Both are 128-bit identifiers in the same format.