UUID Generator

Bee Tools' free UUID generator. Bulk-creates UUID v4 and Nano ID with uppercase, no-dash, braces and length options. Ideal for DB keys and API tokens.

Bulk-generate UUID v4 and Nano ID with format controls. UUID v4 uses the browser's native crypto.randomUUID() API and follows RFC 4122. Nano ID is a 21-character URL-friendly alternative with comparable collision safety. Generate up to 1,000 IDs at a time.

UUID and Nano ID explained

What is a UUID

UUID (Universally Unique Identifier) is defined in RFC 4122. It's 128 bits, typically shown as 32 hex characters in 8-4-4-4-12 groups. UUID v1 is timestamp-based; v4 is random-based and is the most widely used.

Randomness of v4

UUID v4 fills 122 bits with cryptographic randomness; the first 6 bits indicate version and variant. Example:

550e8400-e29b-41d4-a716-446655440000

Generate 1B v4 UUIDs per second, and you'd reach 50% collision only after ~82 years (math-proven).

What is Nano ID

Nano ID was created in 2017 by Andrey Sitnik. A tiny (~130 B) library producing IDs 4× shorter than UUID v4. Uses the URL-safe alphabet A-Za-z0-9_- by default.

Recommended usage

  • DB primary key — store as BINARY(16) to save space.
  • Distributed tracing — UUID v4 is the OpenTelemetry default.
  • API tokens / short links — Nano ID is shorter; combine with HMAC.
  • File names — Nano ID works in URLs out of the box.

Performance

Throughput: UUID v4 ≈ 1.3M/s, Nano ID ≈ 1.8M/s. Nano ID slightly wins in bulk generation.

Click Generate now and feel the joy of getting 100 unique IDs in a few milliseconds.

Open-source notice: UUID v4 uses the browser's native crypto.randomUUID(). Nano ID by ai/nanoid, MIT License. Copyright 2017 Andrey Sitnik.

FAQs

How is UUID v4 generated? Collision probability?
We call the browser's native crypto.randomUUID(), which internally uses crypto.getRandomValues for 122 bits of cryptographic randomness. Collision probability is ~1/2^61 — effectively zero.
Nano ID vs UUID — which is better?
For URLs and APIs Nano ID is shorter; for cross-language compatibility UUID v4 is the industry standard. Both have effectively identical collision properties.
Why is the default length 21?
21 characters give ~126 bits of entropy, matching UUID v4's uniqueness while keeping URLs short.
Could the generated UUIDs repeat?
Mathematically one in trillions. We recommend a dedup check before bulk inserts if needed.
Are my IDs sent to a server?
No. Everything runs in your browser — pull the network cable and it still works.
Can I produce a GUID?
Yes. Wrap a UUID v4 in curly braces for a Microsoft-style GUID; toggle the wrap option.
What is Nano ID's alphabet?
URL-safe A-Za-z0-9_-(64 characters) by default — the same as our tool uses.