UUID Generator
Generate UUID v4 (random) identifiers — one or in bulk.
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How to use this calculator
- 1
Set how many UUIDs to generate (up to 100).
- 2
Choose the format.
- 3
Click Calculate — new UUIDs are generated each time.
Frequently asked questions
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier formatted as 32 hexadecimal digits in 5 groups: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx. There are 5 versions; v4 uses random bits.
Are UUIDs truly unique?
UUID v4 has 122 random bits, giving 2^122 ≈ 5.3 × 10^36 possible values. The probability of generating two identical UUIDs is astronomically small — effectively zero for any real application.
What is the difference between UUID and GUID?
GUID (Globally Unique Identifier) is Microsoft's name for the same concept. They use the same format. In practice, UUID and GUID are interchangeable terms.
UUID v4: random unique identifiers
Why use UUIDs?
UUIDs do not require a central authority to generate — any system can create one independently and be confident it is globally unique. This makes them ideal for distributed systems, database primary keys, file names, session tokens, and API resource identifiers.
UUID vs auto-increment IDs
Auto-increment IDs (1, 2, 3...) are simple but expose information (total record count, creation order) and require a central database to assign. UUIDs are random, unpredictable, and can be generated client-side. The tradeoff: UUIDs are 36 characters vs a compact integer.
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →