ULID Generator
Generates ULIDs: unique like a UUID, but sortable by time — friendlier as a database primary key.
Generate ULIDs online — sortable, time-ordered unique identifiers, ideal for database keys and distributed systems.
Steps and notes
What is ULID Generator — Time-Ordered, Sortable IDs Online?
A ULID is a 128-bit identifier that is lexicographically sortable: the first 10 characters encode a millisecond timestamp, so sorting ULIDs as strings puts them in creation order. That makes them a drop-in upgrade over a random UUID when the identifier is also used as a database primary key or a sort key — new rows land at the end instead of being scattered. The remaining 16 characters are 80 bits of randomness, so collisions are not a practical concern. ULIDs use Crockford base32 (no I, L, O or U) and are conventionally written uppercase.
- Click generate to get a ULID
- Generate repeatedly for more
- Copy and use it
- Each ULID is minted independently, so IDs created in the same millisecond are not guaranteed to sort in generation order — use a monotonic ULID factory when strict insertion order matters
- The quantity field is capped at 100 per refresh; generate more by refreshing again
Frequently asked questions
- How is a ULID different from a UUID v4?
- A UUID v4 is random, so its byte order carries no meaning and sorting it tells you nothing about creation time. A ULID puts a millisecond timestamp in its first 10 characters, so lexicographic order equals chronological order — which is exactly what you want from a primary or sort key.
- Can two ULIDs collide?
- Within a single millisecond a ULID still has 80 random bits (the last 16 characters), giving about 2^80 values before a collision is even theoretically likely. Real systems generate far fewer than that per millisecond, so collisions are not a concern in practice.
- Is a ULID case-sensitive?
- ULID uses Crockford base32 and is conventionally uppercase; the canonical form keeps it uppercase. Some libraries accept lowercase on input, but store and compare the canonical uppercase string to avoid mismatches.
Category: Crypto
ID generators workflow
UUID Generator — v4, v1, v3, v5 and NIL IDs → ULID Generator — Time-Ordered, Sortable IDs Online → Nano ID Generator — Short, URL-safe Unique IDs Online → Token Generator → Password Generator → OTP code generator → BIP39 passphrase generator