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Online GUID / UUID Generator

Generate UUID for uuid types v1, v3, v4 and v5. This tool can be used for Unique ID generation as a sample


Developer Tools

UUID Generator

uuid v4

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Steps to generate Unique Ids using the tool

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  • Select the version of the UUID that is required by clicking on the opton v1, v3 , v4 or v5.
  • If you select Option v1 or v4 , no user inputs are needed
  • If you select Option v3 and Option v5 , you have to provide a namespace and id value.
  • The Namespace is one of the following types: domain, url, oid or any custom text. Select it from dropdown. There are predefined namespaces for each of the types except the custom namespace. For custom namespace, you have to enter a namespace value in the expected format.
  • You also have to enter a Name/Id that can be many unique text of any length.
  • Click on 'Generate' button to generate as per the selected options.
  • Click on the copy icon to copy the generated UUID .
  • Click on Refresh icon to generate a fresh ID.

What is a UUID Generator?

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  • A UUID generator (Universally Unique Identifier) is a tool that can be used to generate universally unique identifiers (UUIGDs).
  • UUIDs are 128-bit values that are guaranteed to be unique across space and time. This makes them ideal for use in a variety of applications, such as database identifiers, file names, and session tokens.
  • There are different versions of UUID generators, including v1, v2, v3, and v4.
  • Here's some information about each of these versions:

  • UUID v1 or UUID1: Version 1 UUIDs are generated based on the current timestamp and the MAC address of the network interface card (NIC) on the generating machine.
    This version includes the potential risk of revealing the MAC address, which can compromise privacy. However, it provides a guaranteed uniqueness within a specific network.
  • UUID v2 or UUID 2: Version 2 UUIDs were defined in the past but are not widely used. They are similar to v1 UUIDs but include additional information, such as the local domain and an identifier representing the local instance. Due to limited adoption, v2 UUIDs are not commonly used.
  • UUID v3 or UUID 3: Version 3 UUIDs are generated using a hashing algorithm, such as MD5 or SHA-1, along with a namespace and a name.
    The resulting UUID is deterministic, meaning that the same inputs will always produce the same UUID. This version is useful when a consistent identifier is needed for a given namespace and name combination.
  • UUID v4 UUID 4: Version 4 UUIDs are generated using a random or pseudo-random number generator. They do not include any meaningful information or guarantee uniqueness based on the generating machine's MAC address. Instead, v4 UUIDs rely on the randomness of the generator to provide a low probability of collisions. This is the most commonly used version of UUIDs today.
  • UUID v5 or UUID 5: Version 5 UUIDS are generated from a namespace UUID and a name. It is a deterministic UUID, meaning that the same name and namespace will always generate the same UUID.

    UUID v5 is generated using the SHA-1 cryptographic hash function. The namespace UUID is a fixed UUID that is used to identify the type of data that the UUID is being generated for. The name is a string of arbitrary length that uniquely identifies the data within the namespace.

    UUID v5 is often used in situations where it is necessary to generate a unique identifier for a piece of data that is not random. For example, it can be used to generate a UUID for a file, a database record, or a user account.

What is the use of UUID generators?

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  • UUIDs are 128-bit values, typically represented as a string of 32 hexadecimal characters separated by hyphens.
  • There are 16 octets of a UUID which are represented as 32 hexadecimal (base-16) digits.
  • It is displayed in five groups separated by hyphen(-), in the form 8-4-4-4-12 which make up a total of 36 characters.
  • There are currently 5 versions of UUID of which v4 is widely followed.
  • UUIDs are designed to be globally unique, The probability of generating the same UUID by different sources is low.
  • The choice of UUID version depends on the specific requirements of the application. For most general use cases, UUID v4 is recommended due to its simplicity and randomness.
  • It's important to note that while UUIDs provide uniqueness, they are not designed to be sequential or sortable. If sequential ordering is required, additional measures need to be taken, such as combining a timestamp with the UUID or using a different identifier scheme.
  • Here are some examples of how UUIDs can be used:
    • UUIDs can be used as session token to authenticate users on a website or an app. The token has limited validity period and typically expires quickly.
    • It can be used in database for storing records - All ID fields mostly use UUID and make it easier during migration of databases and in export and import of data records.
    • It can be used to name files and documents as unique identifiers
    • It can also be used to generate a non duplicate strong initial password or id for first time login after which user can set their own passwords

GUID / UUID Example Table

Type / VersionDescriptionNamespaceName (any value)UUID exampleNotes
v1 (Type 1 / Version 1) Timestamp + Mac Address Not applicable Not applicable 89a10a20-cbbe-11ec-a676-bb300328973c Identifiable pattern based on mac address
v2 (Type 2 / Version 2) Timestamp + User id / group id + Mac address Not applicable Not applicable ac543fb0-a12c-11ec-a676-bb300328973c DCE Security UUIDs similar to v1 with additional user id / group id (Mac + date-time + user id/group id)
v3 (Type 3 / Version 3) ns:DNS(predefined) 6ba7b810-9dad-11d1-80b4-00c04fd430c8 mybrowserappstore c87ee674-4ddc-3efe-a74e-dfe25da5d7b3 namespace base uuid + unique name and MD-5 hash
v3 (Type 3 / Version 3) ns:URL(predefined) 6ba7b811-9dad-11d1-80b4-00c04fd430c8 https://mybrowserappstore.com 14cdb9b4-de01-3faa-aff5-65bc2f771745
v3 (Type 3 / Version 3) ns:OID(predefined) 6ba7b812-9dad-11d1-80b4-00c04fd430c8 oid:123 91bc86a1-765c-310d-829e-7522b0d85e1d
v3 (Type 3 / Version 3) ns:X500(predefined) 6ba7b814-9dad-11d1-80b4-00c04fd430c8 x500:1 5c649c9a-f28f-3b89-9166-9c1b707d513e
v3 (Type 3 / Version 3) Custom (any namespace and name) 12300000-1111-2222-abcd-000000654321 Test a3da4409-9642-3e95-b86c-c2f54c2eb4eb
v4 (type 4 / version 4) random unique number Not applicable Not applicable f3c1b998-081a-41d7-9f6e-c0ebe9b94652 Unique and completely random. Most widely used version
v5 (Type 5 / Version 5) ns:DNS(predefined) 6ba7b810-9dad-11d1-80b4-00c04fd430c8 mybrowserappstore 6cb8e707-0fc5-5f55-88d4-d4fed43e64a8 namespace base uuid + unique name and SHA-1 hash
v5 (Type 5 / Version 5) ns:URL(predefined) 6ba7b811-9dad-11d1-80b4-00c04fd430c8 https://mybrowserappstore.com 1b4db7eb-4057-5ddf-91e0-36dec72071f5
v5 (Type 5 / Version 5) ns:OID(predefined) 6ba7b812-9dad-11d1-80b4-00c04fd430c8 oid:123 695da010-7dba-5010-8eb0-885b11807d1b
v5 (Type 5 / Version 5) ns:X500(predefined) 6ba7b814-9dad-11d1-80b4-00c04fd430c8 x500:1 411e336b-f885-5e78-9c9a-5df247a470d1
v5 (Type 5 / Version 5) Custom (any namespace and name) 12300000-1111-2222-abcd-000000654321 Test 7ba46758-7471-5c2b-83c3-84826c92c359

Frequently Asked Questions on UUID Generator

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  • UUID stands for Universally Unique Identifier.
    They are also called GUID (Globally Unique Identifier).
    The UUID is 128 bits indicated using 32 hexadecimal digits and in 4 parts separated by hyphen (-).
    Example of a unique id (uuid) is 99506172-4ff6-4f5b-a6c5-a1543ee729f3

  • There are 5 versions of UUID - v1, v2, v3, v4 and v5 v1 UUID generates based on timestamp and MAC address of the system where it's generated.
    505cd900-dbch-12db-b10f6-a3a17984572 .
    813214b0-dbch-12db-b10f6-a3a17984572 .
    Note: the 2nd part shows it's from Same machine (dbch-12db-b10f6-a3a17984572).
    v2 UUIDs are DCE Security UUIDs and not much information is except it's similar to version-1 with some additional userid/group id based randomness(Mac + date-time + user id/group id) and based on User id / group id.
    v3 UUID - It generates the UUID using MD5 hash of the inputs (namespace and name as input by user)
    v4 UUID - it generates a completely random number eg: 91de133a-df92-4a5c-996e-94f729e87010 .
    v5 UUID - It generates the UUID using SHA hash of the inputs (namespace and name as input by user).
    If same input is given, it returns the same output.

  • v4 is the standard format.
    It generates secure and completely random numbers.
    v1 generates based on Mac address.
    So if you want to recognize patterns from trusted sources, then v1 can be used.
    If we need same reproducible UUIDs given an name and namespace, then v3 or v5 can be used which provide the UUIDs by using hashing from given name and namespace.
    If name and namespace are same the hash will be same.
    v3 uses MD5 and V5 uses SHA-1

  • UUID is useful wherever we need to uniquely identify objects or resources universally like product, book, person or any entity in backend / storage systems can use UUID.
    Any order, purchase transactions use UUID to uniquely identify the transaction have unique identifiers.

  • v3 and v5 generate UUID of repeatable and consistent formats.
    IF the namespace and name is same, the output is same.
    For repeatability and consistency, these uuid types are used.
    Namespace is a base / seed input which has to be in UUID format.
    THis UUID is used as base to generate.
    Name is any unique digit or string input.

  • DNS — 6ba7b810-9dad-11d1-80b4-00c04fd430c8
    OID — 6ba7b812-9dad-11d1-80b4-00c04fd430c8
    URL — 6ba7b811-9dad-11d1-80b4-00c04fd430c8
    X.500 DN — 6ba7b814-9dad-11d1-80b4-00c04fd430c8

  • No, but versons 3 and 5 generate UUID based on MD5 / SHA1 which hash the input of name and namespace.
    The UUID from v3 and v5 format is similar as it uses hashing algorithm of MD5 and SHA1 respectively

  • 32 digits

  • 128 bits, 16 bytes in big endian order

  • No, they are not case sensitive.

  • In v4, which uses random UUID generator, there is a theoretical chance of collision but probability of actual occurrence is almost nil

  • Yes, both refer to the same thing - Universally / Globally Unique identifiers.
    GUID is coined by Microsoft.
    UUID is from the Open Software Foundation (OSF).