Developer tools

UUID Generator

Generate all eight UUID versions side by side. Use the settings for MAC or node IDs, DCE local identifiers, namespace names, and custom UUIDv8 payloads, then copy the result you need.

8 RFC versions browser-local Read RFC 9562

Generator

Generate UUIDs

UUID's recreated on page refresh or button click

Format

Version settings

MAC / node ID (v1, v2, v6)

Browsers cannot read your MAC address. Enter one to reproduce a node field, or leave this blank for a random privacy-safe node ID.

v2 local identifier

A 32-bit UID, GID, or other identifier meaningful in the selected DCE domain.

v2 local domain

UUIDv2 is a DCE Security compatibility format and is uncommon in new applications.

namespace (v3 / v5)

name (v3 / v5)

The name is UTF-8 encoded before hashing. Same namespace plus name means same UUID.

v8 custom 128-bit payload

UUIDv8 only standardizes its version and variant bits. This value is an experimental application-specific payload, not a guaranteed uniqueness scheme.

Generation, hashing, and settings stay in this browser tab. Nothing entered here is posted to the server or saved.

Results

Ready to generate.

Time-based

Gregorian time + clock sequence + node

Click generate

timestamp MAC / node legacy

Configure with node ID

Useful for legacy interoperability. A real MAC can identify the host, so this page uses a random local node unless you provide one.

DCE Security

Local ID + DCE domain + time + node

Click generate

timestamp local ID MAC / node legacy

Configure with node ID, local ID, and domain

RFC 9562 points UUIDv2 to the DCE specifications. This generator provides the common UID / GID / organization layout for compatibility work.

Name-based · MD5

Namespace UUID + name hashed with MD5

Click generate

name-based deterministic MD5

Configure with namespace and name

Deterministic and interoperable with older systems. Prefer v5 for new name-based designs unless v3 compatibility is required.

Random

122 cryptographically random bits

Click generate

random no MAC general purpose

The familiar default in many platforms. It contains no timestamp, MAC address, name, or sorting signal.

Name-based · SHA-1

Namespace UUID + name hashed with SHA-1

Click generate

name-based deterministic SHA-1

Configure with namespace and name

Use when a stable name must map to the same UUID across systems. The hash is for namespacing, not for password security.

Reordered time-based

v1 fields with timestamp bytes moved first

Click generate

time-ordered MAC / node sort-friendly

Configure with node ID

Designed to improve locality for v1-style workloads. Choose v7 for a new system that does not need v1 compatibility.

Unix time-ordered

Unix epoch milliseconds + random bits

Click generate

time-ordered random sort-friendly

The modern time-ordered choice: timestamp bytes sort first, while the remaining bits provide uniqueness without a MAC address.

Custom / experimental

122 application-defined bits

Click generate

custom payload experimental random

Configure with custom payload

Only the version and variant are standardized. Own the layout and uniqueness rules before using v8 in an interchange format.

Compatibility guide

What your language usually generates

Built-in APIs and database functions often cover only the versions their ecosystem uses most. Always check the version and byte-order contract at the boundary.

.NET / ASP.NET

v4v7 · .NET 9+

Guid.NewGuid() produces v4. Modern .NET also has Guid.CreateVersion7() for v7; the other versions usually come from a library or application code.

Java SE

v3v4

UUID.randomUUID() produces v4 and UUID.nameUUIDFromBytes() produces v3. Java's standard UUID type can inspect older fields, while other versions generally need a library or application code.

Python

v1 · v3 · v4 · v5v6 · v7 · v8 · Python 3.14+

The standard uuid module covers v1, v3, v4, and v5; Python 3.14 adds v6, v7, and v8. UUIDv2 is not part of the standard module.

Node.js / JavaScript

core · v4uuid · v1/v3/v4/v5/v6/v7

Node's built-in crypto.randomUUID() is v4, while recent Node releases also expose v7. The popular uuid package provides v1, v3, v4, v5, v6, and v7; it intentionally leaves v8 application-specific.

What databases generate natively

Native support varies by engine and release. A sequential or binary UUID helper is not automatically UUIDv6 or UUIDv7.

PostgreSQL

v4 · v7 · PostgreSQL 18+

Native v4 and v7 generation: gen_random_uuid() for v4 and uuidv7() for time-ordered v7.

MySQL

v1 · binary(16)

UUID() returns v1. UUID_TO_BIN(..., 1) can reorder v1 time fields for storage, but it does not produce UUIDv6 or UUIDv7.

SQL Server

v4 · sequential GUID

NEWID() produces an RFC 4122-compliant GUID. NEWSEQUENTIALID() is sequential for index locality, but is not UUIDv6 or UUIDv7.

Oracle Database

v4 · Oracle 23ai+

UUID() returns v4 in Oracle Database 23ai and newer. SYS_GUID() remains a 16-byte RAW generator, but it is not labeled as an RFC UUID version.

SQLite

no native UUID · randomblob(16)

SQLite has no UUID type or versioned UUID generator. randomblob(16) plus hex() can make random 128-bit text, but applications must set UUID v4 bits themselves.

MongoDB

v4 · mongosh UUID() · ObjectId ≠ UUID

UUID() in mongosh generates random v4 BSON UUIDs. The default ObjectId is a separate 12-byte identifier, not one of UUID v1-v8.

Sorting

v6 and v7 put time first so opaque byte or text sorting follows creation time. They are useful for database locality; v1's legacy field order is not naturally lexicographically sorted.

MAC / node privacy

v1, v2, and v6 have a node field. It may be a MAC address or a random value. This page never discovers a browser MAC, and its blank setting uses a random multicast node.

UUIDv8 is not a magic hash

v8 reserves 122 bits for your format; it does not promise global uniqueness. Document the payload, versioning, and collision strategy alongside your application.