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UUID Generator

Generate and locally verify UUID v4, RFC 9562 UUID v7, and monotonic ULID batches with explicit presentation and export formats.

LocalNo retention

Reviewed July 13, 2026

Guide, examples, and validation Show

About this tool

Generate UUID v4, UUID v7, or monotonic ULID identifiers locally for apps, databases, seeds, and test fixtures, with batches up to 1,000 values.

UUID Generator is useful when development work needs trustworthy random identifiers right away for seeds, fixtures, docs, request IDs, or manual testing. It is faster than opening a REPL or writing a script when the task is simply producing one ID or a clean batch of IDs.

  • Uses uuid 14 for UUID v4 and RFC 9562 UUID v7, and ulid 3 for monotonic Crockford Base32 values.
  • Checks syntax, UUID version and variant, embedded time, batch duplicates, and applicable lexical ordering before export.
  • Generates up to 1,000 identifiers and exports one-per-line, comma-separated, or JSON array output.

How to use UUID Generator

Generate a single UUID or a batch, then copy only the amount you need into your config, test data, or documentation. If you are pairing generation with QA, run the output through the validator or sample it in the target system so you can confirm the expected version and format.

When this tool is useful

  • Uses uuid 14 for UUID v4 and RFC 9562 UUID v7, and ulid 3 for monotonic Crockford Base32 values.
  • Checks syntax, UUID version and variant, embedded time, batch duplicates, and applicable lexical ordering before export.
  • Generates up to 1,000 identifiers and exports one-per-line, comma-separated, or JSON array output.

Examples you can test

Load an example, compare the result with the expected output, then replace it with your own input.

Generate a fixture ID

Example input

Count: 1, version: v4

Expected output

Random UUID v4

Useful for seed data, mock API responses, support examples, and documentation snippets.

Create a batch of test IDs

Example input

Count: 5

Expected output

Five UUID values, one per line

Batch output helps prepare sample rows without manually running a script.

Validation checklist

  • Use generated UUIDs for identifiers, not for passwords or secrets.
  • Confirm the target system accepts the UUID version and casing.
  • Avoid reusing the same sample ID when uniqueness matters.

Frequently asked questions

What UUID and ID types does this tool support?

The tool generates three types: UUID v4 (random), UUID v7 (time-ordered, RFC 9562), and ULID (Universally Unique Lexicographically Sortable Identifier with Crockford Base32 encoding).

Are generated UUIDs unique?

The tool checks that a generated batch contains no duplicates. UUID and ULID uniqueness outside that batch remains probabilistic and is not checked against an external registry.

Which implementations generate and validate the identifiers?

The browser build uses uuid 14 for UUID v4 and v7, and ulid 3 with its browser-selected secure random source for monotonic ULIDs. The tool validates syntax, UUID version and variant, timestamps, ordering, and batch duplicates locally before enabling export.

Can I generate multiple UUIDs at once instead of clicking repeatedly?

Yes. Generate up to 1,000 identifiers, copy individual preview rows or the complete batch, and download text or JSON output.

What is the difference between UUID v4 and UUID v7?

UUID v4 uses entirely random bytes, while UUID v7 embeds a millisecond-precision timestamp followed by random bits. This makes v7 values time-sortable, which improves database index performance.

What display formats are available for generated IDs?

UUID values support canonical lowercase, uppercase, braces, and URN presentation. ULIDs support canonical uppercase and lowercase. Presentation changes do not alter the verified canonical values.

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