UUID Generator
Bulk v4 and v7 UUIDs from your browser's crypto API
Version 4 UUIDs are entirely random. Use them when values must reveal nothing about when they were created.
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How to use
The version you choose matters more than most people expect. Version 4 is fully random; version 7 embeds a timestamp so values sort chronologically. That single difference determines how your database index behaves under load.
Pick a version
Choose v4 when the identifier must reveal nothing about creation time. Choose v7 when values will become database keys and you want inserts to append rather than scatter.
Set the quantity
Generate between 1 and 500 at a time. Bulk generation is useful for seeding fixtures or pre-allocating identifiers.
Copy what you need
Copy an individual value with the button beside it, or take the whole list newline-separated with the copy control in the toolbar.
Examples
A version 4 UUID
A value such as 9f2c8d61-4b7a-4e29-b1f3-2a7c5e8d0b41 carries 122 bits of randomness. The chance of a collision remains negligible even across billions of values.
Version 7 for database keys
Consecutive v7 values share a leading timestamp, so they sort in creation order and land adjacently in a B-tree index. Random v4 keys scatter writes across the index, which measurably hurts insert throughput on large tables.
About this tool
Generate UUIDs in bulk, in version 4 or version 7. Values come from the Web Crypto API, never from Math.random, so they are suitable for real identifiers rather than only for testing. Copy them individually or all at once.