ULID Generator
Generate ULIDs (Universally Unique Lexicographically Sortable Identifiers) in your browser. No upload, fully private.
Local processingWhat is ULID Generator?
A ULID (Universally Unique Lexicographically Sortable Identifier) is a 128-bit identifier encoded as 26 characters of Crockford base32. It consists of a 48-bit millisecond timestamp followed by 80 bits of randomness, producing IDs that are sortable by creation time and collision-resistant.
How It Works
The generator takes the current millisecond timestamp (48 bits) and 10 random bytes from crypto.getRandomValues (80 bits), then encodes the combined 128 bits into 26 characters using the Crockford base32 alphabet (0-9, A-Z excluding I, L, O, U).
Common Use Cases
- Database primary keys that sort by creation time
- Distributed system identifiers with natural ordering
- Log entry correlation IDs that sort chronologically
Technical Details
Spec: ULID (github.com/ulid/spec). Encoding: Crockford base32. Timestamp: 48-bit milliseconds since Unix epoch. Randomness: 80 bits from CSPRNG. Length: 26 characters. Sortable: lexicographic order matches chronological order within same millisecond.
How to Use
- Set the number of ULIDs to generate
- Click Generate
- Copy the results
Privacy
All processing happens in your browser. Your data is never uploaded to any server.
FAQ
What is a ULID?
A ULID is a 26-character, lexicographically sortable, 128-bit identifier that combines a millisecond timestamp with random entropy, making it ideal for ordered storage.
Why use ULID instead of UUID?
ULIDs are sortable by time, shorter as strings (26 vs 36 chars), and encode as URL-safe Crockford base32, making them better for database indexes and logs.
Are ULIDs uploaded or stored?
No. ULIDs are generated entirely in your browser using crypto.getRandomValues. Output is never transmitted.