Category

Identifiers

Every tool and article in this category, gathered in one place.

Tools

UUID Generator & Inspector (v4 / v7)
Generate random v4 or time-ordered v7 UUIDs, or paste any UUID to read its version, variant, and (for v7) the embedded creation timestamp. Generation uses the browser's secure random source. Runs entirely in your browser.

Articles

UUIDs: random v4 and time-ordered v7
How a 128-bit identifier stays unique without a central authority, and why v7 is becoming the default for database keys.
Read
UUID versions explained: v1 through v8
The whole UUID family in one place, from time-and-MAC v1 to random v4 to time-ordered v7, plus the name-based versions and how the version and variant bits are read.
Read
Will UUIDs collide? Probability and the birthday bound
How many random bits a UUID actually has, the birthday math for a collision, and when you want deterministic UUIDs instead.
Read
UUIDs as database keys: v4, v7, and index locality
The real trade-off between UUIDs and auto-increment integers, and why random v4 keys quietly hurt database performance.
Read
ULID, KSUID, Snowflake, and other sortable IDs
The popular alternatives to UUIDs for time-ordered identifiers, how each is built, and why UUIDv7 now covers most of what they were invented for.
Read