Generate unique UUIDs (v1, v4) for your applications
Choose version and quantity
Generate universally unique identifiers (UUIDs) instantly. Support for Version 1 (time-based) and Version 4 (random) UUIDs. Perfect for developers, database administrators, and testers. This tool runs entirely in your browser, ensuring that your generated IDs are private and never sent to a server.
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. It is virtually guaranteed to be unique across all devices and time, making it ideal for distributed systems where coordination between different components is difficult. It is typically represented as a 32-character hexadecimal string, displayed in five groups separated by hyphens (e.g., 8-4-4-4-12).
UUID v1 is generated using a timestamp and the MAC address of the computer (or a random node ID). It is useful when you need to sort IDs by creation time, but it can potentially reveal the MAC address of the generating machine. UUID v4 is generated using random numbers and provides a higher degree of randomness and privacy, making it the industry standard for most applications, including database primary keys and API tokens.
While not theoretically impossible, the probability of a collision (two identical UUIDs being generated) is astronomically low. To put it in perspective, you would need to generate 1 billion UUIDs per second for about 85 years to have a 50% chance of a single collision. For all practical purposes in software development, UUID v4 is considered unique.
Sequential IDs (1, 2, 3...) are simple but can expose information about your data volume (e.g., 'user/100' implies 100 users). They also cause conflicts in distributed databases where multiple servers might try to create ID '101' simultaneously. UUIDs solve these problems by being non-sequential, unguessable, and globally unique without requiring a central authority to issue them.
Why generate UUIDs in your browser?
Server-side generation is necessary when you need to ensure uniqueness against a central database immediately, but for generating identifiers for new data, client-side generation is the standard modern approach.
Need multiple UUIDs? Our tool allows you to generate up to 100 UUIDs at once. This is particularly useful for populating test databases, generating batch API keys, or creating unique session tokens for load testing.
You don't need a plugin to generate UUIDs in Excel. You can use this formula (for recent versions):
`=LOWER(CONCAT(DEC2HEX(RANDBETWEEN(0,4294967295),8),"-",DEC2HEX(RANDBETWEEN(0,65535),4),"-",DEC2HEX(RANDBETWEEN(16384,20479),4),"-",DEC2HEX(RANDBETWEEN(32768,49151),4),"-",DEC2HEX(RANDBETWEEN(0,4294967295),8),DEC2HEX(RANDBETWEEN(0,65535),4)))`
Alternatively, on Windows, you can use PowerShell: `[guid]::NewGuid()`.
They are essentially the same thing. UUID (Universally Unique Identifier) is the standard term defined by RFC 4122. GUID (Globally Unique Identifier) is the term Microsoft uses. In practice, they are interchangeable 128-bit numbers. If you are a .NET developer, you say GUID; if you use Java or Python, you say UUID.
Most programming languages have built-in support or libraries for UUID generation:
When storing UUIDs in a database (like MySQL or PostgreSQL), you have two main options:
Recommendation: Use BINARY(16) for production databases with millions of rows.
Generate unique identifiers for your applications
Choose between UUID v4 (random) or UUID v1 (time-based). v4 is recommended for most use cases.
Enter the number of UUIDs you want to generate (1-100).
Click 'Generate UUIDs' to create unique identifiers.
Click the copy icon next to any UUID to copy it to your clipboard, or copy all at once.