A ULID (Universally Unique Lexicographically Sortable Identifier) is a 128-bit identifier combining a 48-bit millisecond-precision timestamp with 80 bits of random data. Unlike standard UUIDs, ULIDs are sortable by creation time, making them ideal for databases and distributed systems where chronological ordering matters. They're URL-safe and more human-readable than traditional UUIDs.

How do I use this ULID Generator?

Step 1: Visit the tool and select your desired mode (Standard, Bulk, or Monotonic). Step 2: For bulk generation, enter the number of ULIDs you need. Step 3: Click the 'Generate' button to create your identifiers. Step 4: Copy the generated ULIDs from the output area. Step 5: To decode a ULID, paste it in the decoder section to reveal its embedded timestamp and creation time. All processing happens instantly in your browser.

Is this ULID Generator free?

Yes, this ULID Generator is completely free to use at tools.bkns.vn. There are no limits on how many ULIDs you can generate, no registration required, and no hidden fees. All processing occurs securely in your browser with no data tracking or server storage.

What's the difference between standard and monotonic ULIDs?

Standard ULIDs use random bits for the entire 80-bit random component, resulting in identifiers with full randomness. Monotonic ULIDs increment the random portion when generated within the same millisecond, ensuring strict ordering even for rapid consecutive generations. Choose monotonic mode when you need guaranteed sequential ordering in high-throughput scenarios.

Can I decode a ULID to see its timestamp?

Yes, the decoder extracts the 48-bit timestamp from any valid ULID and displays the exact creation date and time in millisecond precision. This is useful for auditing, debugging, and verifying when identifiers were generated. Simply paste the ULID into the decoder field and view the timestamp immediately.

ULID Generator - Free online tool

ULIDs are composed of a 48-bit timestamp (millisecond precision) followed by an 80-bit random component, creating identifiers that are sortable by creation time while remaining globally unique. When you use this generator, it reads your system's current time and encodes it into the ULID structure alongside cryptographically random bits, ensuring each identifier is both unique and chronologically orderable.

The tool offers multiple modes for different needs: standard generation creates individual ULIDs with random components, bulk mode generates multiple ULIDs in a single operation, and monotonic mode ensures sequential ordering even when generating multiple ULIDs within the same millisecond. The timestamp decoder extracts and displays the original creation time from any ULID, making it easy to verify when an identifier was generated.

All computation occurs entirely in your browser using JavaScript, meaning your data never leaves your device. This approach provides both privacy and performance, with no server round-trips required for generation or decoding operations.

Database Primary Keys - Use ULIDs as sortable, time-ordered primary keys in applications requiring both uniqueness and chronological ordering without relying on auto-increment sequences.
Distributed Systems - Generate globally unique identifiers across multiple servers or microservices without coordination, avoiding ID collision issues in distributed architectures.
API Request Tracking - Assign ULIDs to incoming requests for reliable tracking, logging, and correlation across service boundaries while maintaining temporal ordering.
Event Sourcing - Create chronologically ordered event identifiers in event-driven architectures, making it simple to reconstruct sequences and audit trails.
Bulk Data Operations - Generate hundreds or thousands of unique identifiers simultaneously for batch import operations, data migration, or seeding development environments.

ULID Generator

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Common Use Cases

Frequently Asked Questions