I often have to generate random UUIDs so I created this simple online utility that does it for me. It lets you generate however many random universally unique identifiers you need with any version number and variant number. It works in the browser and is powered by alien technology from the future.

Random Uuid Generator Options

UUID Version
Generate date-time and MAC address UUIDs.
Generate DCE date-time and MAC address UUIDs.
Generate namespace name-based UUIDs.
Generate random number UUIDs.
Generate namespace name-based UUIDs.
UUID Variant
Uses bit pattern "0xxx" that corresponds to hex digits 0-7.
Uses bit pattern "10xx" that corresponds to hex digits 8-b.
Uses bit pattern "110x" that corresponds to hex digits c-d.
Uses bit pattern "111x" that corresponds to hex digits e-f.
Count and Format
Split UUIDs with hyphens in the format 8-4-4-4-12.
Add curly brackets around UUIDs.
Make all hex digits in UUIDs uppercase.
Add uniform resource name (URN) namespace to UUIDs.

Random Uuid Generator Examples (click to try!)

Random v4v1 UUIDs
In this example, we generate ten random version-4 and variant-1 UUIDs (UUIDv4v1). The identifier version and variant are determined by the values M and N in the UUID pattern "xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx". The value M is the version and N is the variant. As we're generating version-4 UUIDs, M is set to "4". For variant-1 UUIDs, the value N uses the bit pattern "10xx" with two free bits. It can take values "1000", "1001", "1010", and "1011". Converted to hex, N is limited to values "8", "9", "a", and "b". The UUIDs in the output are displayed one per line and use the separator "\n" between them.
b505d776-f1e8-4cf9-a9fa-22e488693deb
a0428c39-61f2-4ce4-9c8d-659f6c37d218
a42634b9-0c0a-4d7d-a697-e28d0b318819
704fbd23-98bc-4e72-b747-0edae1d681d1
bae0ed8b-dbd6-4ce3-986d-8548b88986a4
da729b7e-976b-42a5-8cfb-2270063e2926
c2ee8e66-7644-427a-a4b0-4d0a86f7fc7e
90aa1111-992e-47fe-9e01-eb9b9e28efc2
e59efdf7-be3c-461c-b949-016b72798f32
050f72ed-d5d1-4339-b261-bb1ead9e5c1e
Generate Version 1
Generate Version 2
Generate Version 3
Generate Version 4
Generate Version 5
Generate Variant 0
Generate Variant 1
Generate Variant 2
Reserved Variant
How many UUIDs to generate?
Separate UUIDs with this symbol.
Use Hyphens
Wrap in Curly Braces
Uppercase UUIDs
Use URN Namespace
All Versions and Variants
In this example, we allow the generator to use all identifier versions and all variants to generate all possible types of UUIDs. Identifier versions include date-time and MAC address (ver1), DCE security (ver2), namespace name-based (ver3 and ver5), and random number UUIDs (ver5). The variants can use bit patterns "0xxx" (var1), "10xx" (var2), "110x" (var3), or "111x" (reserved variant). We generate 8 comma-separated UUIDs, wrap them in curly brackets to make them GUID-like, and add the URN namespace prefix to them.
urn:uuid:{e35991e0-e330-1730-12e3-1b82c3a8a190}, urn:uuid:{f1629784-3401-185f-0521-90415fa45179}, urn:uuid:{bba794f2-4988-1b03-39db-f4969fe2d38e}, urn:uuid:{68652ad2-45a1-1882-4856-5952a820f4f2}, urn:uuid:{7614eb3c-77e1-1745-1b39-c36cd463e689}, urn:uuid:{42eeebb6-6147-1d4e-78a3-0f9e717d71fb}, urn:uuid:{f66def4f-c018-1e7d-4a5a-956e4210eea6}, urn:uuid:{37cb89d7-1b46-198a-640f-fe6284d1fe85}
Generate Version 1
Generate Version 2
Generate Version 3
Generate Version 4
Generate Version 5
Generate Variant 0
Generate Variant 1
Generate Variant 2
Reserved Variant
How many UUIDs to generate?
Separate UUIDs with this symbol.
Use Hyphens
Wrap in Curly Braces
Uppercase UUIDs
Use URN Namespace
Reserved UUIDs
In this example, we generate reserved UUIDs. Reserved UUIDs have the variant nibble set to "e" or "f", which correspond to bit patterns "1110" and "1111". We also set the version to 2, which is reserved by RFC 4122 and often isn't implemented. In total, we generate 5 reserved UUIDs, make them upper case, and print them in the output field.
3A403EA6-A991-2061-EFCC-1BF1DA1F9FF4
E4C6A120-8011-2303-E4C9-54D18495BAC5
2A79F5FC-5A18-2774-F4B6-44E85A079083
6176424D-71A3-2D7E-F5D3-41C6DF011C3C
2DAA089D-3DEE-2BA8-EA59-0AD0EF046A71
Generate Version 1
Generate Version 2
Generate Version 3
Generate Version 4
Generate Version 5
Generate Variant 0
Generate Variant 1
Generate Variant 2
Reserved Variant
How many UUIDs to generate?
Separate UUIDs with this symbol.
Use Hyphens
Wrap in Curly Braces
Uppercase UUIDs
Use URN Namespace

How Does This Random Uuid Generator Work?

This random UUID generator works entirely in your browser and is written in JavaScript. A UUID is a unique identifier that is a 16-byte (128-bit) hexadecimal number that's often used in databases and software development. By default, it consists of five hyphen-separated groups in the format xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx, which the program keeps in the pattern variable. If the hyphens are disabled, the pattern is set to xxxxxxxxxxxxMxxxNxxxxxxxxxxxxxxx. The values x are arbitrary and can take any hex digit from 0-f but the values M and N are special and can take only certain values. To create random UUIDs, the program starts a for loop and runs it count times (this variable can be changed in the options and it determines how many UUIDs will be printed in the output). In the loop, it replaces the letters x, M, and N in the pattern with random values. The digit x is a random hexadecimal number calculated by the expression parseInt(Math.random()*16, 10).toString(16). The digit M is the UUID version. It can be selected in the options and can take values from 1 to 5. When you select one or more versions, they are put into the array ver and then picked at random via the expression ver[Math.floor(Math.random() * ver.length)]. The digit N is the UUID variant. It also can be selected in the options and can take hex values from 0 to f. We store all selected variants in the var array and choose a random hex value via var[Math.floor(Math.random() * var.length)]. After replacing all the letters in the pattern with hex values, it's push()ed to the uuids array. When the loop ends, depending on the additional selected options, the generator calls uuids.map() function to wrap UUIDs in braces, add URN namespace, and to convert hex digits to uppercase. Finally, the elements of the uuids array are concatenated together thru the separator character and are printed to the screen.

Created by Browserling

This random uuid generator was created by me and my team at Browserling. Behind the scenes, it's actually powered by our programmer tools that are used by millions of people every month. Browserling itself is an online cross-browser testing service powered by alien technology. Check it out!

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