Random UUID Generator

Generate RFC‑4122 v4 UUIDs

Quickly produce standard RFC‑4122 v4 UUIDs you can copy and paste for IDs, test data, filenames, tracing, and more. This generator on PicoToolkit returns 36‑character hyphenated UUIDs like the example below.

How to use

• Click the generator to create a new UUID. Copy it where you need a globally unique identifier.
• Output format: 36 characters with hyphens (8-4-4-4-12). Example: 57920f21-469d-4b99-88ec-df38e3ada784.
• For bulk testing, generate many UUIDs and paste them into your test data, import tool, or script.

Common use cases

• Database surrogate keys where predictable sequence is not required.
• Temporary filenames or object keys to avoid collisions.
• Correlation / trace IDs for logs, requests, and distributed tracing.
• Generating unique test data for QA and automated tests.

Examples

• Single UUID (copyable): 57920f21-469d-4b99-88ec-df38e3ada784
• JavaScript (example of equivalent generation):

  crypto.randomUUID() // produces a v4 UUID in modern browsers

• Python (example using uuid module):

  import uuid
  str(uuid.uuid4())  # e.g. '57920f21-469d-4b99-88ec-df38e3ada784'

Tips & edge cases

• UUID v4 is random (≈122 bits of randomness). Collisions are extremely unlikely but not impossible; for critical systems consider collision checks at insertion time.
• Do not use UUIDs as secrets or authentication tokens. They are not a substitute for cryptographic keys or signed tokens.
• If database index fragmentation or write hot spots are a concern, consider using time-ordered IDs (ULID/KSUID) or a UUID v1 alternative.
• If you need shorter, human-friendly IDs, consider encoding the UUID (base62) or using NanoID instead.
• For deterministic reproducible IDs, do not use random UUIDs — consider namespace-based UUIDs (v3/v5) or your own scheme.

FAQ

Is this a cryptographically secure UUID?

v4 UUIDs rely on random bits. Whether they are cryptographically secure depends on the underlying RNG used by the environment. Use dedicated cryptographic tokens for secrets.

Can I remove the hyphens?

Yes — many systems accept UUIDs without hyphens. Removing hyphens changes the string format but not the uniqueness properties of the underlying 128‑bit value.

How likely is a collision?

Collisions are astronomically unlikely for v4 UUIDs at typical scales. For extremely large volumes (billions+), include application-level checks if collision tolerance is zero.