ULID Generator
Create Universally Unique Lexicographically Sortable Identifiers in your browser for records, jobs, logs, and test data.
A QUICK WALKTHROUGH
How to use this tool
- Choose how many ULIDs to generate, from 1 to 100.
- Generate the identifiers and review the newline-separated result.
- Copy the batch or download it as a UTF-8 text file.
Standard ULID structure
Each ULID is 26 characters: 10 Crockford Base32 characters encode a 48-bit Unix millisecond timestamp, followed by 16 characters encoding 80 random bits. The result uses uppercase letters and digits, excluding I, L, O, and U.
Sortable by time, unique by randomness
ULIDs generated at different millisecond timestamps sort chronologically with ordinary lexicographic string comparison. Values generated in the same millisecond are ordered by their random portion and are not guaranteed to increase unless a monotonic ULID algorithm is used.
Local generation and practical limits
Generation happens in this browser with crypto.getRandomValues and the values are never sent to a server. This page accepts batches of 1 to 100 ULIDs and provides copy and UTF-8 TXT download actions.
GOOD TO KNOW
Common questions
What encoding does a ULID use?
This generator uses the standard Crockford Base32 alphabet, 01ABCDEFGHJKMNPQRSTVWXYZ, in uppercase.
Do ULIDs always sort in generation order?
They sort by millisecond timestamp first. Multiple values made in the same millisecond are random and therefore are not guaranteed to retain generation order.
Does the generator use a server?
No. Timestamp and random bytes are produced locally in your browser.
Are ULIDs passwords or encrypted values?
No. A ULID is an identifier, not a secret or encryption mechanism.