Need a unique identifier for a database row, a request, a file, or a test fixture — without coordinating with any central service? This free uuid generator mints random version 4 UUIDs in your browser, one at a time or in bulk. Everything runs in your browser, so nothing is uploaded, no account is needed, and no signup stands between you and the result.
How to use this uuid generator
Three quick steps — no signup, no cost.
One UUID for a single record, or a batch for seeding test data and fixtures.
Lowercase or uppercase hex, with dashes as standard, without dashes for compact form, or wrapped in braces where a system expects them.
Fresh values appear instantly. Copy one, copy the whole batch, or download the list as a text file.
Why this uuid generator is safe to trust for real identifiers
Randomness from the operating system, not from a toy generator.
Values come from the browser’s Web Crypto API — crypto.randomUUID() or crypto.getRandomValues() — never from Math.random(), which is not suitable for identifiers.
Each UUID is 128 bits rendered as 8-4-4-4-12 hexadecimal groups, with the version digit 4 and the correct variant bits in their fixed positions.
Generate a batch for seeding databases, migration scripts, and test fixtures, then copy or download the whole list at once.
Generation happens entirely on your device, so the identifiers you mint are never seen, logged, or stored by any server.
Version 4, version 7, or something else? Pick by what the ID is for
Version 4 is the default in this tool. The others exist for specific jobs, not as upgrades.
Version 4 (this tool): the safe default. Pure randomness — 122 random bits — with no timestamp and no machine information embedded, so nothing leaks about when or where it was created. Use it for general-purpose unique IDs, session tokens, and request IDs.
Version 7: for database primary keys that get inserted constantly. It embeds a millisecond timestamp in its high bits, so new values sort by creation time and land at the end of a database index instead of scattering randomly through it. If insert order and index performance matter, v7 is the better pick — but this tool does not generate it.
Version 1 and NIL: legacy and sentinel only. Version 1 embeds a timestamp and a machine address, which can leak identifying information, so it survives for compatibility, not for new work. NIL — all zeros — is a placeholder meaning ‘no value yet’, not an identifier to assign.
UUID and GUID are the same thing. UUID is the standard term; GUID is Microsoft’s name for the identical format. Values are case-insensitive by specification, so compare them lowercased if two systems disagree on casing.
UUID Generator FAQs
Short, direct answers to the questions readers ask most.
It creates unique identifiers for database primary keys, session tokens, API request IDs, file names, and distributed systems that need uniqueness without a central authority.
Effectively yes. Version 4 carries 122 bits of cryptographically secure randomness from the browser’s Web Crypto API, making a collision vanishingly unlikely at any realistic scale.
In theory yes, but the probability is so small — roughly 1 in 5.3 x 10^36 possible values — that collisions do not happen in practice.
Nothing in the format: UUID is the standard term and GUID is Microsoft’s term for the same 128-bit identifier.
Yes. It runs entirely in your browser with no account, no signup, and nothing uploaded or logged.
Related Tools
More free converters that work the same way — right in your browser.
Flatten JSON data into plain text lists.
TXT to CSV ConverterTurn plain-text rows into CSV tables.
CSV to JSON ConverterConvert CSV tables into JSON data.
JSON to CSV ConverterTurn JSON arrays into CSV rows.
Try the related tools above, or go back to the Convertion homepage for more free converters.
