ULID Generator
What is an ULID Generator?
Generate 128-bit Universally Unique Lexicographically Sortable Identifiers (ULID). Combines a 48-bit millisecond timestamp prefix with 80 bits of random entropy encoded in Crockford's Base32.
Why Use This Tool?
- Database B-Tree Index Optimization: Replace random UUID v4 keys with time-ordered ULIDs to prevent database index fragmentation.
- URL-Friendly Unique IDs: Generate 26-character URL-safe identifiers without hyphens.
- Monotonically Increasing Keys: Sort records chronologically directly by primary key string.
How to Use
- Select Quantity (e.g. `10`).
- Click Generate ULID.
- Copy 26-character Crockford Base32 ULID list.
Real Working Example
Input:
Quantity: 5 | Target: ULID Generation
Output Result:
01ARZ3NDEKTSV4RRFFQ69G5FAV 01ARZ3NDEKTSV4RRFFQ69G5FAW 01ARZ3NDEKTSV4RRFFQ69G5FAX 01ARZ3NDEKTSV4RRFFQ69G5FAY 01ARZ3NDEKTSV4RRFFQ69G5FAZ
Important Technical Details & Security Standards
- ULID Specification Compliance: 128-bit total size (48-bit timestamp + 80-bit randomness), 26-character Crockford Base32 encoding.
- Crockford Base32 Alphabet: Uses `0123456789ABCDEFGHJKMNPQRSTVWXYZ` (excludes I, L, O, U to avoid misreading).
- Local Memory Execution: Fast local generation in browser memory.
Related Security & Crypto Tools
- UUID Generator: Generate UUID v4 and v7.
- Token Generator: Generate random tokens.
- Base64 Encoder/Decoder: Encode Base64 strings.
Frequently Asked Questions
What is a ULID?
A ULID (Universally Unique Lexicographically Sortable Identifier) is a 128-bit time-sortable identifier formatted as 26 Crockford Base32 characters.
Why are ULIDs better than UUID v4 for database primary keys?
ULIDs are time-ordered, preventing B-Tree index page splitting and accelerating SQL insert performance compared to random UUID v4.
Why does Crockford Base32 exclude letters I, L, O, and U?
To prevent human reading errors and guard against accidental visual confusion with digits 1, 0, or offensive words.
Is it free?
Yes, 100% free.
Can ULID strings be sorted chronologically?
Yes, ULID strings sort chronologically using standard lexicographical string sorting.
Are generated ULIDs saved on a server?
No, all generation executes 100% locally in your web browser.