Generate & Decode Universally Unique ULIDs
Create 128-bit lexicographically sortable Crockford Base32 ULIDs and decode millisecond timestamps from any ULID.
About This Tool
ULID (Universally Unique Lexicographically Sortable Identifier) is a 26-character, 128-bit identifier compatible with UUIDs. Unlike UUIDv4, ULIDs are time-ordered and sort naturally in databases, indexing significantly faster in B-trees.
Key Features
Standard 26-character Crockford Base32 encoding
Batch generation (up to 50 ULIDs)
Built-in timestamp decoder and inspector
Uppercase and lowercase formatting
How to Use This Tool
- Set batch quantity (1 to 50) and toggle lowercase if desired.
- Click 'Generate ULIDs' to create a list of sortable identifiers.
- Paste any existing ULID into the Inspector to decode its exact creation date and UTC timestamp.
Why Use This Tool
- Provides millisecond timestamp precision combined with 80 bits of cryptographic randomness.
- Superior database indexing performance compared to random UUIDs.
Pro Tips
- ULIDs use Crockford's Base32 alphabet which eliminates ambiguous characters like I, L, O, and U
Frequently Asked Questions
Why choose ULID over UUIDv4?
ULIDs are 128-bit like UUIDs, but because the first 48 bits encode the timestamp, they sort in chronological order, preventing database index fragmentation.