UUID Generator
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. It is also known as a GUID (Globally Unique Identifier) in Microsoft technologies.
UUIDs follow the pattern 8-4-4-4-12 and look like this: 550e8400-e29b-41d4-a716-446655440000. Most importantly, they are designed to be unique across both space and time without any central authority.
How to use this UUID generator
Simply click “Generate” to create a new UUID instantly. You can then click the display box or the “Copy” button to copy it to your clipboard. Additionally, use the Version dropdown to choose between v4 (random) and v1 (timestamp-based).
For bulk generation, select the number of UUIDs you need (up to 100) and click “Generate bulk”. After that, use “Copy all” to copy all generated UUIDs at once. Furthermore, the Format dropdown lets you get UUIDs without dashes, in uppercase, or with curly braces.
UUID versions explained
Version 4 (Random)
This is the most commonly used version. It provides 122 bits of randomness, making collisions virtually impossible. As a result, v4 UUIDs are suitable for database primary keys, session tokens, and API identifiers.
Version 1 (Timestamp)
This version incorporates the current timestamp. Therefore, v1 UUIDs are roughly sortable by creation time. However, they may reveal when they were created, which is a consideration for privacy.
Common use cases
Developers use UUIDs as database primary keys in distributed systems where auto-incrementing integers are impractical. Similarly, many REST APIs use UUIDs to identify resources, sessions, and transactions. In addition, UUIDs are popular for file naming to prevent collisions when storing user uploads.
Frequently asked questions
Are UUIDs truly unique?
For v4 UUIDs, the probability of a collision is approximately 1 in 5.3 x 10^36. In practice, this means they are considered unique for all real-world applications.
Can I use UUIDs as database primary keys?
Yes, UUIDs are widely used as primary keys, especially in distributed systems. However, random UUIDs (v4) can cause index fragmentation in some databases. Therefore, consider using v1 if ordering matters.
Is my data safe?
Absolutely. All UUIDs are generated locally in your browser using JavaScript. Nothing is sent to any server.
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