When is UUID Generator useful?
UUID v4 identifiers are useful for test fixtures, sample records, import drafts, and local data where a value should not collide with nearby examples. This page generates a batch in the browser, one identifier per line, with options for lowercase or uppercase letters and for keeping or removing hyphens. The result can be copied directly into a script or downloaded as a text file.
The generator uses crypto.randomUUID when available. Its fallback obtains random bytes from the browser crypto source and applies the version and variant bits required by UUID v4 before formatting the value. Count is limited to 1000 per run so a phone stays responsive. Removing hyphens changes only presentation; it does not create a new namespace or make an identifier more secure.
Uniqueness is probabilistic, not absolute. A collision means two generated values are equal, and its likelihood depends on how many values are created and how trustworthy the random source is. For access tokens or identifiers that must be reserved globally, use the system that owns the database and security policy. This page does not check a database and does not upload the generated list.
The output is intentionally plain text so it can be imported into a fixture or pasted into a list field. Before using a generated value as a database key, check the destination column type and whether the system already generates its own identifiers. UUIDs are not ordered timestamps, and removing hyphens does not make them sortable or shorter in a meaningful storage sense. A batch generated in one tab is not registered anywhere. If two systems must agree that an identifier is unused, the authoritative system still has to reserve or check it. Use the count control for a bounded batch rather than generating an unreviewed stream.