Data tools

UUID Generator

Generate cryptographically secure RFC 4122 UUID v4 values in several output formats.

Processed locally in your browser. Your input is not uploaded to our server.

UUID appearance

Choose options, then generate UUIDs locally.

How to use UUID Generator

  1. Choose a batch size from 1 to 1,000.
  2. Select line, comma, JSON, or SQL output plus casing, hyphen, and brace options.
  3. Generate, validate the displayed batch, then copy or download it locally.

Supported behavior

UUID Generator creates RFC 4122 version 4 identifiers from cryptographically secure browser randomness. It uses crypto.randomUUID when available and a crypto.getRandomValues fallback otherwise, then validates version and variant formatting. Generate from one to 1,000 values and format them one per line, comma-separated, as a JSON array, or as an SQL quoted list. Optional uppercase, hyphen removal, and surrounding braces change presentation without changing the underlying random identifier bits. Results can be copied or downloaded, and no generated identifier is sent to analytics or any server. Because generation happens entirely in your browser, there is no central registry, account, or sequence. Version 4 UUIDs have an extremely low collision probability but do not provide absolute uniqueness, ordering, secrecy, or proof of identity. Do not use a UUID as a password, authorization token, timestamp, or database existence check; apply application-level uniqueness constraints where collisions would be consequential.

  • Version 4 UUIDs are random and therefore cannot produce a deterministic example output.
  • Random UUIDs do not encode creation time and should not be treated as secrets or guarantees of uniqueness.

Examples

                Count: 1; format: one per line

Result: A newly generated value matching xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx, where y is 8, 9, a, or b

                Count: 3; format: SQL quoted list; uppercase: on

Result: Three newly generated uppercase UUID v4 values in a comma-separated quoted list

Common use cases

  • Create IDs for local test fixtures and sample records.
  • Prepare a quoted UUID list for a development SQL query.
  • Generate client-side correlation identifiers without contacting a service.

Frequently asked questions

Which UUID version is generated?

RFC 4122 version 4, with the required version and variant bits.

How many can I create at once?

The supported batch range is 1 through 1,000.

Are hyphenless values still based on UUID v4?

Yes. Removing hyphens changes only the output presentation of the generated UUID.

Can the same UUID ever appear twice?

A collision is extremely unlikely but not mathematically impossible, so critical stores should enforce uniqueness.