ID Toolkit
All processing happens in your browser. No data is sent to any server.
Frequently Asked Questions
What is UUID v1?
UUID v1 is a 128-bit identifier that embeds a 60-bit Gregorian timestamp (100-nanosecond intervals since 1582-10-15), a 14-bit clock sequence, and a 48-bit node identifier (typically a MAC address, or a random value with the multicast bit set).
What is UUID v4?
UUID v4 is a 128-bit identifier where 122 bits are randomly generated. It uses the format xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx where 4 indicates the version and y is the variant (8, 9, a, or b).
What is UUID v7?
UUID v7 is a time-ordered UUID that embeds a 48-bit Unix millisecond timestamp in the first 48 bits, followed by random data. This makes v7 UUIDs naturally sortable by creation time.
When should I use ULID instead of UUID?
ULID is a good choice when you need lexicographically sortable IDs that encode a timestamp. ULIDs are 26 characters in Crockford Base32, making them URL-safe and slightly more compact than UUIDs.
When should I use KSUID?
KSUID is ideal when you need time-sortable 27-character IDs with second-level precision. KSUIDs use a custom epoch (2014-05-13) and 128 bits of random payload for strong uniqueness.