ULID Generator
Generate sortable, URL-safe, 26-character unique ULIDs and decode their timestamps.
Decode a ULID
What is a ULID?
A ULID (Universally Unique Lexicographically Sortable Identifier) is a 26-character ID combining a 48-bit millisecond timestamp with 80 random bits. It uses the Crockford Base32 alphabet, is case-insensitive and safe in URLs. Example: 01ARZ3NDEKTSV4RRFFQ69G5FAV
Advantage over UUID
UUID v4 is completely random, so inserts land all over database indexes and can hurt performance. ULIDs sort by creation time, keeping indexes efficient, and sorting records by ID gives chronological order.
Features
- Bulk ULID generation
- Monotonic mode that keeps ordering within the same millisecond
- Decode an existing ULID's timestamp as a date
Generation happens in your browser.
How to use ULID Generator
- Choose how many ULIDs to generate.
- Turn on monotonic mode if needed.
- Generate and copy the ULIDs.
- Paste a ULID into the decode field to see when it was created.
Why use this tool?
A practical way to produce sortable, short and readable IDs for distributed systems and databases.
FAQ
What does monotonic mean?
IDs created in the same millisecond increment by one instead of being fully random, so they still sort in creation order.
Can I store a ULID in a UUID column?
Yes. A ULID is also 128 bits and can be converted to UUID format for storage.
Can I get the creation time from a ULID?
Yes. The first 10 characters encode the timestamp and the tool converts it to a date.
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