Developer & Data

UUID & ID Generator

Bulk UUID v4/v7, ULID, NanoID, slugs and secure tokens.

Generate identifiers

Identifier inspector

Paste any UUID or ULID to decode its version, variant and timestamp.

Paste an identifier and press Inspect.

About UUID & ID Generator

Generate identifiers in bulk offline: UUID v4 and v7, ULID, NanoID, cryptographically secure tokens, numeric ranges, invoice and order number series with prefixes, plus a UUID inspector that decodes version and timestamp.

What it does

How to use it

  1. Choose the identifier type you need, such as UUID v4 or ULID.
  2. Set how many you want and any prefix, suffix or case option.
  3. Press Generate; the identifiers appear immediately and can be copied or downloaded.
  4. Paste an existing UUID into the Inspector to see its version, variant and embedded timestamp.

UUID & ID Generator is one of 50 free tools from CRMTECH Solutions. See all Developer & Data tools or browse every tool.

Frequently asked questions

Are these identifiers really random?

Yes. Every random byte comes from crypto.getRandomValues, the browser's cryptographically secure generator. They are not produced from Math.random, which would be predictable.

When should I use UUID v7 instead of v4?

UUID v7 starts with a millisecond timestamp, so identifiers sort in creation order. That makes database indexes far more efficient than with v4, which scatters writes across the whole index. Use v7 for primary keys and v4 when ordering must not be inferable.

What is a ULID?

A 26-character Crockford Base32 identifier: 48 bits of timestamp followed by 80 bits of randomness. It sorts lexicographically by creation time, is case-insensitive and avoids the characters I, L, O and U so it cannot be misread.

Can two identifiers collide?

For UUID v4 the probability is negligible: you would need to generate about a billion per second for 85 years to reach a 50% chance of one collision. The tool also checks the batch it just produced and reports if any duplicate appeared.

Is the sequential business number series safe for invoices?

It formats numbers correctly, but the counter is per user, not a shared company-wide sequence. For real invoicing, keep the authoritative counter in your accounting system and use this to preview or backfill a format.

Is UUID & ID Generator free?

Yes. UUID & ID Generator is free for everyone and needs no sign-up to use. An account is only needed to export, download or print, because every export is recorded.

Are my files uploaded to a server?

No. UUID & ID Generator works inside your web browser, so the files you open are processed on your own device. If you sign in, the work you save (such as drafts and registers) is also kept in your account so it follows you to other devices.

Does it work on a phone?

Yes. It works in current versions of Chrome, Edge, Safari and Firefox on phones, tablets and computers, with nothing to install.