🆔 UUID Generator
Generate universally unique identifiers (UUID v4) instantly. Generate one or bulk UUIDs with a single click.
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📖 What is a UUID?
A UUID (Universally Unique Identifier), also known as GUID (Globally Unique Identifier), is a 128-bit identifier that is guaranteed to be unique across all devices and all time. UUIDs are represented as 32 hexadecimal digits, displayed in five groups separated by hyphens: 8-4-4-4-12.
UUID v4 (random) is the most commonly used version. It generates identifiers using cryptographically secure random numbers, making collisions virtually impossible — the probability of generating two identical UUIDs is about 1 in 5.3 × 10^36.
UUIDs are widely used in databases as primary keys, distributed systems for unique resource identification, session tokens, file naming, and API request tracking.
❓ Frequently Asked Questions
While theoretically possible, the probability is astronomically small. With UUID v4, you would need to generate about 2.71 quintillion UUIDs to have a 50% chance of a collision. In practice, UUIDs are considered unique.
UUID and GUID are essentially the same thing. UUID (Universally Unique Identifier) is the standard term used in most contexts, while GUID (Globally Unique Identifier) is Microsoft's term. Both refer to 128-bit identifiers in the same format.
UUIDs are great for distributed systems where you can't use auto-incrementing IDs. However, they are larger (16 bytes vs 4 bytes for int) and can cause index fragmentation. Consider your specific use case and database requirements.