wire / identifier / uuid-max

Max UUID (all-ones)

The Max UUID is the special UUID with all 128 bits set to one: ffffffff-ffff-ffff-ffff-ffffffffffff. RFC 9562 defines it as a sentinel that sorts after every other UUID — useful as an exclusive upper bound in range scans. Its version and variant nibbles are both 0xF, so it matches no real version.

identifier kind identifier status standard verification verified tier B identifier@1

aka: max UUID · omni UUID · all-ones UUID

identifier

spec: RFC 9562 §5.10

length 128 bits not sortable hex with dashes (8-4-4-4-12)

example:

ffffffff-ffff-ffff-ffff-ffffffffffff

fieldbitsmeaning
all_one128Every bit is 1. Version nibble = 0xF and variant nibble = 0xF, so it is not a valid v1-v8 value.

provenance

see also

agent: curl -H 'accept: application/json' wire.phall.io/identifier/uuid-max or /identifier/uuid-max.json