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

Random Guid Generator Options

GUID Version
Generate GUID version-1.
Generate GUID version-2.
Generate GUID version-3.
Generate GUID version-4.
Generate GUID version-5.
GUID Variant
Generate one-bit GUID variant-0.
Generate two-bit GUID variant-1.
Generate three-bit GUID variant-2.
Generate reserved three-bit GUID variant.
Output Size and Format
Separate GUID groups with hyphens.
Wrap GUIDs in curly braces.
Convert hexadecimal values in GUIDs to uppercase.
Prepend URN namespace before GUIDs.

Random Guid Generator Examples (click to try!)

Name-based GUIDs
In this example, we generate namespace name-based GUIDs by activating the version-3 and version-5 options. We use the bit patterns "10xx" and "110x" for the variants, which correspond to hex digits 8, 9, a, b (pattern "10xx") and c, d (pattern "110x"). We create a total of eight random GUIDs, wrap them in curly brackets, and separate them by the newline character "\n".
{61d0f615-1c17-384d-a7a5-1c56e95d4dc0}
{bbc9167e-842e-3b25-9ab1-03263ec585e4}
{761d2d38-c004-3c5d-b40b-55daaf5b5be5}
{c80ee270-d239-3516-acdd-2494bfcef211}
{a4d38748-768b-3c62-b19f-8850d172ea68}
{e6f365ce-5a85-3b6d-8064-25e0fc43a58e}
{38ea9946-c9a9-3377-b666-727253307a90}
{f8cb4fea-7304-365e-8f6f-f3090fd7c426}
Date-time/Mac GUID
DCE Security GUID
Name-based GUID
Random GUID
Name-based GUID
Bit Pattern 0xxx
Bit Pattern 10xx
Bit Pattern 110x
Bit Pattern 111x
How many GUIDs to generate?
Separate GUIDs with this character.
Use Group Separator
Use Curly Brackets
Use Uppercase Letters
Use Uniform Resource Name
Random v2v2 GUIDs
In this example, we generate twelve non-hyphenated GUIDs with both version and variant numbers equal to 2. The version-2 is the date-time/MAC address/DCE security GUID. The variant-2 uses the pattern "110x" for the B nybble. There is one free bit in this pattern and it can be either "1100" or "1101". These two values correspond to hex nybbles "c" and "d". We output all GUIDs on the same line and separate them with a space character.
{5c163324dc132398c20a660001fc6941} {e92f445dd8422c67d1e72f979793aaf2} {edb3f5fc187324d6c701246fd146b2ad} {3af5bc1e794c20f3c42caa2433f31e35} {0fe441224a812905df68ae90fac2f63f} {a4c2472034da2962cf5555c42a356af1} {1dce853873bb2e69c6c5e43e170c9100} {e4e7846e70962199c99d0000ad681188} {a4f118e6e60422adc93c7484cc5e068a} {2379e7d1400926aec72490d3c5c6d573} {2f66f899e9cd23b8dbc82898cd2d701e} {b60093d00eb62933d0aec07037979464}
Date-time/Mac GUID
DCE Security GUID
Name-based GUID
Random GUID
Name-based GUID
Bit Pattern 0xxx
Bit Pattern 10xx
Bit Pattern 110x
Bit Pattern 111x
How many GUIDs to generate?
Separate GUIDs with this character.
Use Group Separator
Use Curly Brackets
Use Uppercase Letters
Use Uniform Resource Name
All GUID Variants
This example prints randomly generated version-4 GUIDs with all variants allowed. This means that the variant matches any of the patterns "0xxx", or "10xx", or "110x", or "111x1" and takes any hexadecimal number from 0 to f. We create ten uppercase random GUIDs and output them one per line.
{8C0408BB-03F0-4A95-3684-8CE77B961F2B}
{ABA8F601-67F2-444E-451E-7BEC497D00DA}
{30D409DB-E0D6-4A9E-3E19-05E422A7AB6A}
{89604608-EB58-4DCE-6008-7E344F81A247}
{93AE4DB2-F162-4ECA-5DE8-852826A74A8B}
{26F300E3-E267-420E-562A-C1CA386AE28D}
{051F26F3-4781-47EF-063E-97BEE144A7FE}
{A21F76B0-40F8-4506-6C88-EF6FC2478E9D}
{42E27711-B89E-4C88-609C-A989985DDCB8}
{A4E3075D-81C6-45AB-5669-A392E011ECE1}
Date-time/Mac GUID
DCE Security GUID
Name-based GUID
Random GUID
Name-based GUID
Bit Pattern 0xxx
Bit Pattern 10xx
Bit Pattern 110x
Bit Pattern 111x
How many GUIDs to generate?
Separate GUIDs with this character.
Use Group Separator
Use Curly Brackets
Use Uppercase Letters
Use Uniform Resource Name

How Does This Random Guid Generator Work?

This random GUID generator works entirely in your browser and is written in JavaScript. A GUID (Globally Unique Identifier) as defined in RFC 4112 is a 128-bit number that allows information to be identified in a unique way. The probability of two pieces of information having two identical keys is astronomically low. A GUID is usually represented as a string of 32 hex digits that are divided into five hyphen-separated groups of sizes 8-4-4-4-12 and enclosed in curly braces: {dddddddd-dddd-Addd-Bddd-dddddddddddd}. To generate random GUIDs, the program assigns this string to the variable format and replace()s the letters d with hex digits, and letters A and B with GUID version and GUID variant. To generate a hex digit for the d character, it calls the chooseOne function with an array of all hex digits as its argument chooseOne(['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f']). This function randomly picks and returns one of the elements in the array by selecting a random index in it arr[parseInt(arr.length*Math.random())]. The letter A denotes the GUID version and can take values from 1 to 5. In the options, you can select which versions you want to generate. Depending on the activated versions, the program fills the array versions with possible values. For example, if you selected versions 2 and 3, then versions is set to [2, 3]. Then it randomly selects one of the versions by calling chooseOne(versions). The letter B denotes the GUID variant and can vary from 0 to f. The possible variants are also configurable in the options and their values are stored in the variants variable. Similar to versions, the code to select a random variant is chooseOne(variants). Depending on the value count, the program loads and replaces the format string multiple times in a for loop. Each generated GUID is pushed to the array guids. When the loop finishes, the program uses the function map() to adjust the output GUIDs format and they are printed to the screen via the console.log function.

Created by Browserling

This random guid 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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