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ULID Generator
Generate sortable unique identifiers (ULIDs).
Overview
- Generates multiple ULIDs (Universally Unique Lexicographically Sortable Identifiers), which can be sorted by timestamp.
- The first 48 bits are a millisecond-precision timestamp, so — unlike a UUID — a ULID can also be sorted as a plain string in generation order.
- Uses Crockford's Base32 encoding, which excludes the easily confused letters I, L, O, and U, reducing mistakes when a person copies it by hand.
Usage
- Specify the number of ULIDs to generate.
- Click the "Generate" button.
- 26-character ULIDs are displayed for the specified count. Use the "Copy" button to copy the result to the clipboard.
Example
Input
Count: 1
Output
01ARZ3NDEKTSV4RRFFQ69G5FAV
Use Cases
- Issuing sortable ULIDs instead of UUIDs as database primary keys where insertion order matters
- Preparing an identifier for a log or event record that is easy to sort by generation time
- Issuing multiple unique event IDs for a distributed system, each carrying embedded timestamp information
FAQ
What's the difference between a ULID and a UUID?
A ULID's first 48 bits are a millisecond-precision timestamp, so ULIDs can be sorted as strings in generation order. The remaining bits are random.
Which character set does it use?
It uses Crockford's Base32 encoding, which excludes the easily confused letters I, L, O, and U.
Are generated ULIDs sent anywhere?
No. They are generated entirely in your browser using the Web Crypto API, and nothing is sent to an external server.
Notes
- The generated result exists only on the page and is lost on reload, so copy any value you need right away.
- Up to 50 can be generated at once. Generate multiple times if you need more.
- The timestamp portion reveals roughly when it was generated, so this is not suitable for uses where the time needs to stay hidden.
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