UUID / GUID generator

Client

Create cryptographically strong random UUID v4 values for IDs, test data, and placeholders. Choose how many to emit, optional uppercase GUID style, and a separator—everything runs in your browser.

Using this page

Pick a count, separator (newlines or commas), and whether you want uppercase hex. Generate fills the list; use copy actions for tickets or spreadsheets. Values are RFC 9562 random UUID v4 (version nibble 4, variant bits 10).

When UUID vs shorter IDs

UUIDs are long and ubiquitous in databases and logs. For time-ordered standard UUID shape, see UUID v7. For URL-friendly shorter tokens with similar “unguessable” intent, compare Nano ID (configurable length) and ULID (lexicographically sortable by time). Pair any of these with the timestamp converter when you are correlating ids with log lines.

Options

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Version 4 identifiers use random bits (RFC 9562). They are suitable for request IDs, keys, and placeholders—use a dedicated system if you need guaranteed uniqueness across distributed databases.

Separator

Nearby workflows on Toolcore

  • UUID v7 — when you need time-ordered standard UUID syntax instead of random v4.
  • ULID generator — for shorter Crockford base32 ids that still sort by timestamp.
  • Nano ID — when URLs need a compact alphabet with configurable length.

Common use cases

  • Generate RFC 9562 random UUID v4 values for database primary keys and API ids.
  • Create many unique ids at once for fixtures, load tests, or mock services.
  • Copy a batch as newline- or comma-separated text for spreadsheets or tickets.
  • Hand out fresh ids during API design reviews when you want stable 128-bit string shape without starting the backend.

Common mistakes to avoid

  • Assuming UUIDs are always secret

    UUID v4 values are random, but anyone who sees one can reference the same record. Do not use them as authentication tokens by themselves.

  • Relying on uppercase in all systems

    The canonical string is lowercase hex with hyphens. Some systems normalize case; others compare literally—pick one style per integration.

  • Confusing version numbers

    This page generates version 4 (random). For time-ordered UUID v7 (RFC 9562), use the separate UUID v7 generator at /tools/uuid/v7.

FAQ

Are these UUIDs cryptographically strong?

They are generated with your browser’s cryptographically strong random source when available, suitable for typical application identifiers.

Does generation run on your servers?

No. Values are created locally in your tab and never sent to Toolcore.

Can I get UUIDs without hyphens?

Use copy options in the workspace if provided, or remove hyphens in your editor—the underlying value is the same 128-bit id.

Are these IDs ordered by creation time?

No. Version 4 UUIDs are random; they do not sort by mint time. For UUID v7 (timestamp + randomness) try /tools/uuid/v7, or ULID at /tools/ulid for base32 time ids.

Common search terms

Phrases people search for that match this tool. See the full long-tail keyword index.

  • uuid generator online
  • guid generator free
  • uuid v4 batch generator

More tools

Related utilities you can open in another tab—mostly client-side.