TSV
UUID/GUID (Universally/Globally Unique Identifier) - TSV
UUID (Universally Unique Identifier) and GUID (Globally Unique Identifier) are 128-bit unique identifiers used in software systems. Standardized by RFC 4122 and RFC 9562, they can be generated independently without a central coordinating authority and have an extremely low probability of duplication. They are widely used for database primary keys, distributed system identifiers, API keys, and more.
UUID
GUID
identifier
RFC 4122
RFC 9562
database
distributed systems
code slug name description algorithm recommended sortable
v1 uuid-v1 UUIDv1 (Gregorian Time-Based) Time-based UUID using timestamp and MAC address. Time-based + MAC address false true
v2 uuid-v2 UUIDv2 (DCE Security) DCE Security UUID with embedded POSIX UID/GID. DCE Security with POSIX ID false true
v3 uuid-v3 UUIDv3 (Name-Based, MD5) Name-based UUID generated using MD5 hash of namespace and name. MD5 hash of namespace + name false false
v4 uuid-v4 UUIDv4 (Random) The most commonly used random-generated UUID. Random 122 bits true false
v5 uuid-v5 UUIDv5 (Name-Based, SHA-1) Name-based UUID generated using SHA-1 hash of namespace and name. SHA-1 hash of namespace + name true false
v6 uuid-v6 UUIDv6 (Reordered Time-Based) Field-compatible reordering of UUIDv1 with improved database locality. Reordered UUIDv1 timestamp false true
v7 uuid-v7 UUIDv7 (Unix Epoch Time-Based) The recommended modern time-based UUID using Unix timestamp. 48-bit Unix timestamp + 74-bit random true true
v8 uuid-v8 UUIDv8 (Custom) Implementation-defined custom UUID format for experimental use. Implementation-defined custom false