UUID & ULID Generator

Bulk UUID v4/v7 and ULID, generated with crypto randomness.

Generate UUIDs (v1, v4, v7) and ULIDs in bulk and copy them instantly. Free online UUID generator that runs in your browser — no signup, nothing logged.

About UUID & ULID Generator

The UUID & ULID Generator is a free, browser-based tool that creates batches of unique identifiers — RFC 4122/9562 UUID v4 (random) and v7 (time-ordered), ULIDs, and the Nil UUID — using your browser's Web Crypto randomness. It also inspects any pasted UUID or ULID to decode its version, variant, and embedded timestamp. Everything runs locally with no signup, so no IDs are ever sent to a server.

How to use UUID & ULID Generator

  1. Open the Generate tab and pick a format: UUID v4, UUID v7, ULID, or Nil.
  2. Set how many to create with the Count slider (1 to 100); Nil always returns a single all-zeros value.
  3. Toggle formatting for UUIDs as needed — UPPERCASE, hyphens on/off, braces {…}, or a urn:uuid: prefix (ULID stays Crockford base32).
  4. Click Regenerate to produce the list using Web Crypto random bytes.
  5. Copy a single ID, use Copy all, or download every value as ids.txt.
  6. Switch to the Inspect / decode tab and paste any UUID or ULID to see its version, variant, raw hex, and timestamp.

Frequently asked questions

Is it free, and do I need an account?
Yes, it is completely free with no signup. The tool runs entirely in your browser.
Are the IDs uploaded or sent anywhere?
No. Generation and decoding happen locally in your browser using the Web Crypto API — nothing is sent to a server, so no identifier ever leaves your device.
Which UUID versions and ID types are supported?
It generates UUID v4 (fully random, 122 bits of entropy), UUID v7 (millisecond timestamp plus random, sortable), ULID (Crockford base32, lexicographically sortable), and the Nil UUID (all zeros). The output follows the canonical 8-4-4-4-12 UUID format and RFC 4122/9562.
How many can I generate at once?
Between 1 and 100 per click using the Count slider. The Nil UUID ignores count since every value is identical. Copy all of them at once or download them as a .txt file.
How random are the UUIDs?
They use crypto.getRandomValues (the browser's Web Crypto API), the same cryptographically strong source recommended for security-sensitive randomness — not Math.random.
What can the Inspect tab tell me?
Paste any UUID (v1, v4, v7, Nil, or Max) or a ULID and it decodes the format, variant (RFC 4122/9562, Microsoft GUID, etc.), the raw 16 bytes, and any embedded timestamp in UTC and your local time. Braces and urn: prefixes are stripped automatically.

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