Cloanto UUID/GUID Generator (Public Version)

This free service by Cloanto generates Version 1 UUIDs (Universally Unique Identifiers) as per ISO/IEC-11578, RFC-mealling-uuid-urn-05.txt and Microsoft's GUID implementation.

Unique by Design

The service was built to produce unique UUIDs by design, rather than by relying on randomness.

The following are some of the mechanisms that are employed:

• The spatially-unique node identifier field uses a unique IEEE 802 address (00-50-C2-49-00-48, from a range assigned by IEEE to Cloanto) reserved by Cloanto for this specific service
• The clock sequence field is initialized using a cryptographic-quality algorithm
• The timestamp field is set by using the UTC time on the system where the service is running, which in turn synchronizes its clock with external sources to minimize drifting
• If necessary, a delay is added before generating a new timestamp to ensure that the new timestamp is newer than the previously-issued one
• A semaphore guarantees that multiple requests are processed in sequence

Notes

In order to maintain a reasonable level of performance, the service generates a maximum of 5000 UUIDs per request.

Usual disclaimers apply. In particular, while we have made every effort to ensure that there is no duplication of issued UUIDs, we cannot guarantee that duplicate UUIDs have not been issued.

Notice for Cloanto users: please use the intranet form, not this one (the 00-50-C2-49-00-48 range has been reserved for public use, not for internal use).

Feel free to contact us with any questions and feedback you may have.

Request UUIDs