UUID Generator

Generate UUIDs (v1, v3, v4, v5, v7) online instantly, single or in bulk — free UUID generator.

Format

Versions 1, 4 and 7 are randomly generated (7 is timestamp-ordered, good for database keys). Versions 3 and 5 are deterministic — the same namespace + name always produces the same UUID.

About

About the UUID Generator

Generates UUIDs in versions 1, 3, 4, 5 or 7, either randomly or deterministically from a namespace and name.

Developers use it to generate primary keys and unique identifiers for databases and APIs without spinning up any code, while QA engineers use it to produce a batch of unique test IDs at once. It's one of many free generators on Toolapt, and like every tool here, it's free to use with no sign-up and no limit on how many times you run it.

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Guide

Using the UUID Generator

  1. 1

    Step 1

    Choose a UUID version from the dropdown — version 4 (random) is selected by default.

  2. 2

    Step 2

    For versions 1, 4 and 7, set how many UUIDs to generate; for versions 3 and 5, pick a namespace and type a name.

  3. 3

    Step 3

    Optionally turn on uppercase or "no hyphens" formatting.

  4. 4

    Step 4

    Click "Generate" to create the UUID(s), then "Copy" to copy them, or "Clear" to start over.

  • Supports UUID versions 1, 3, 4, 5 and 7, matching the RFC 4122/9562 specifications
  • Versions 1, 4 and 7 are generated from the browser's cryptographically secure random source (crypto.getRandomValues)
  • Version 7 embeds a millisecond timestamp, so IDs generated later always sort after earlier ones
  • Versions 3 and 5 are deterministic hashes of a namespace and name, so the same input always gives the same UUID
  • Generates up to 500 UUIDs at once, with optional uppercase and no-hyphen formatting
  • Works entirely in your browser — no installs and no sign-up
  • Free to use, with no limit on how many times you run it
  • Fully responsive, so it works just as well on a phone as on a desktop

Developers

Developers use the UUID Generator for primary keys, API resource IDs and test fixtures without writing a line of code.

QA engineers

QA engineers use the UUID Generator for producing a batch of unique identifiers at once to seed test data.

Database administrators

Database administrators use the UUID Generator's version 7 option for sortable, timestamp-ordered keys that still index well.

Anyone building name-based systems

Anyone building name-based systems uses the UUID Generator's version 3 and 5 options for deterministic IDs that are always the same for the same input.

Examples

UUID Generator examples

4 worked examples

01

Deterministic name-based UUID (v5)

Using the DNS namespace with the name "example.com" and version 5 always produces the same UUID, cfbff0d1-9375-5685-968c-48ce8b15ae17, so the same namespace and name give the same ID every time.

02

Deterministic name-based UUID (v3)

The same DNS namespace and name "example.com" with version 3 (MD5-based) instead gives 9073926b-929f-31c2-abc9-fad77ae3e8eb — a different value from v5 because the two versions hash with different algorithms.

03

Random UUID (v4)

Clicking Generate with version 4 selected produces a random 36-character ID such as 3f2504e0-4f89-41d3-9a0c-0305e82c3301, with no relationship between successive UUIDs.

04

Sortable UUID (v7)

Generating several version 7 UUIDs in a row embeds the current millisecond timestamp in each one, so IDs created later always sort after ones created earlier, unlike v4.

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FAQ

Frequently asked questions

Quick answers to common questions about the UUID Generator.

What does the UUID Generator do?

It generates universally unique identifiers in version 1, 3, 4, 5 or 7, either randomly or deterministically from a namespace and name.

Is the UUID Generator free to use?

Yes. It's free, with no sign-up, no watermark and no limit on how many times you use it.

Is my input safe when I use this tool?

Yes. Every UUID is generated entirely on your own device — nothing is sent to a server.

Which version should I use?

Version 4 is the most common general-purpose choice. Use version 7 if you want IDs that sort chronologically (good for database keys), and version 3 or 5 if you need the same input to always produce the same UUID.

What's the difference between version 3 and version 5?

Both hash a namespace UUID plus a name into a deterministic UUID; version 3 uses the older MD5 hash and version 5 uses SHA-1, which is preferred where compatibility with version 3 isn't required.

Are the random UUIDs cryptographically secure?

Yes. Versions 1, 4 and 7 all draw their random bits from crypto.getRandomValues, the browser's secure random source, not Math.random().

Can I use the UUID Generator on my phone?

Yes. The page is fully responsive and works on mobile, tablet and desktop browsers alike.

Does the UUID Generator have any limitations?

It generates up to 500 UUIDs per batch for versions 1, 4 and 7, and one UUID at a time for the name-based versions 3 and 5.

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