How unique are your UUIDs really?
Total UUIDs Generated
315.58 billion
Collision Probability
9.3652e-15
In Human Terms
Less likely than guessing a random 10-digit phone number
Probability Meter
100.00%
You'd need to generate 1 billion UUIDs per second for 85 years to have a 50% chance of a single UUID v4 collision.
The number of possible UUID v4 values (5.3 x 10^36) exceeds the estimated number of grains of sand on Earth (7.5 x 10^18) squared.
If every person on Earth generated 600 million UUIDs per second, after 100 years the probability of a single duplicate would still be about 50%.
You're more likely to be hit by a meteorite while being struck by lightning than to generate two identical UUID v4s in most practical applications.
UUID v4 has more possible combinations than there are atoms in a human body (~7 x 10^27).