Free UUID/GUID Generator

The UUID Generator is a free online tool that creates universally unique identifiers (UUIDs/GUIDs) for use in databases, APIs, and software development.

Yes, it is completely free with no registration required. All UUIDs are generated client-side in your browser.

Yes, UUIDs use random number generation with such a large space (2^128) that the probability of generating duplicates is practically zero.

Absolutely. The UUID/GUID Generator processes everything client-side in your browser. No data is uploaded to or stored on any server. Your content remains private on your device at all times.

Yes, the UUID/GUID Generator is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.

No account or registration is needed. Simply open the UUID/GUID Generator in your browser and start using it immediately. There are no sign-up walls or usage restrictions.

Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.

The UUID/GUID Generator works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.

There is no real difference: UUID (Universally Unique Identifier) and GUID (Globally Unique Identifier) are two names for the same thing — a 128-bit value written as 32 hexadecimal digits in five hyphen-separated groups, like f47ac10b-58cc-4372-a567-0e02b2c3d479. "UUID" is the term used by the RFC standard and most languages, while "GUID" is Microsoft's name for it, common in .NET, SQL Server, and the Windows registry. The only practical wrinkle is formatting: Microsoft APIs often wrap the value in curly braces, like {f47ac10b-...}. The values themselves are interchangeable. This generator produces standard UUIDs and lets you output them in braces, uppercase, or other GUID-friendly styles, so the same tool covers both worlds — pick a version and format above to get exactly what your code expects.

UUID v4 is fully random — all 122 usable bits come from a cryptographically secure source, so the values are unpredictable but appear in no particular order. UUID v7 instead puts a Unix millisecond timestamp in its high bits and fills the rest with randomness, so newer IDs sort after older ones. That ordering matters for databases: random v4 keys scatter inserts across an index and cause page fragmentation, while time-ordered v7 keys append near the end and keep the index compact and cache-friendly. Choose v4 when you want maximum unpredictability and no information leakage, and v7 as a modern default for primary keys in new tables where insert performance counts. This generator supports both, plus v1, v3, v5, and NIL — select a version above and generate to compare the formats side by side.

A deterministic UUID is one that always comes out the same for the same input, rather than being random. Versions 3 and 5 work by hashing a namespace UUID together with a name string — v3 uses MD5 and v5 uses SHA-1 — so feeding in the same namespace and name (say, a URL or email address) reliably reproduces the identical UUID every time. That is useful when you need a stable, collision-resistant ID derived from existing data: deduplicating records, generating predictable keys for cache entries, or mapping external identifiers without storing a lookup table. Prefer v5 over v3 for new work, since SHA-1 is the stronger hash. To use it here, choose v5, pick a namespace (DNS, URL, OID, X.500, or a custom one), type your name string, and the tool produces the same reproducible identifier on every run.

A UUID's version is encoded in a fixed spot: the first character of the third hyphen-group tells you the version number. So in 018f3e2a-7c11-7abc-9def-0123456789ab the leading 7 of "7abc" marks it as a v7, while a 4 there would mean v4. The following group's first character signals the variant. For time-based versions you can go further and recover the creation time, because v1 embeds a 60-bit timestamp counted in 100-nanosecond intervals since 1582 and v7 embeds a plain Unix millisecond timestamp. Paste any identifier into this tool's validator and it confirms whether the value is well-formed, reports its version and variant, and — for v1 and v7 — decodes the embedded timestamp into a readable date, so you can sanity-check IDs straight from a log or database dump.

The hyphens in a UUID are purely cosmetic. The canonical text form splits the 32 hexadecimal digits into five groups (8-4-4-4-12) joined by dashes for readability, but the hyphens carry no data — strip them and you are left with the same 32-character value, like f47ac10b58cc4372a5670e02b2c3d479. Many systems prefer the compact form: it is shorter in URLs, avoids delimiter issues in filenames, and fits cleanly into fixed-width database columns. Some APIs also expect the braces or urn:uuid: forms instead. A dashless UUID is still valid and converts back to the standard layout without losing information, since the grouping is fixed. This generator can output every identifier in lowercase, uppercase, no-dashes, braces, or urn:uuid: form, and it accepts those variants in the validator too — choose your format above and copy the exact style your code needs.