Crypto
ULID Generator
Generate 26-character identifiers containing a millisecond timestamp and random suffix for records or log fixtures.
About this tool
When to use it
Generate 26-character identifiers containing a millisecond timestamp and random suffix for records or log fixtures.
How to use it
Choose the batch size, select Generate ULIDs, and copy or download the values. Treat the encoded time as client-clock information rather than a trusted server timestamp.
Guide updated . Examples checked against this implementation.
Worked examples
Recognize the generated format
Input
How many: 1Expected output
26 uppercase Crockford Base32 characters; a new value for each generationThis is a shape example. The timestamp occupies the leading portion, and randomness distinguishes values generated at the same time.
Errors and unsupported input
IDs generated in one millisecond do not sort in insertion orderThis implementation uses independent random suffixes, not a monotonic ULID sequence. Store a separate ordering field if exact event order is required.
Continue this workflow
- UUID Generator: Generate UUID v4 values when timestamp information is unnecessary.
Questions
Frequently asked questions
Can I use the ULID time as an audit timestamp?
It reflects the generator's clock, which may be wrong or manipulated. Record authoritative audit times in the trusted system.