About UUID Generator
Universally Unique Identifiers (UUIDs) are 128-bit identifiers used to uniquely identify objects in distributed systems without a central authority. This tool generates three popular formats: UUID v4 (random), UUID v7 (time-ordered, suitable for database primary keys), and ULID (Universally Unique Lexicographically Sortable Identifier). Generate single or bulk identifiers instantly.
How to Use
- Select the identifier type: UUID v4, UUID v7, or ULID.
- Set the count (1–50) for bulk generation.
- Click "Generate" to create your identifiers.
- Click "Copy" on any individual result or "Copy all" for the full list.
Key Features
- ✓ Generate cryptographically random UUID v4
- ✓ Generate time-ordered UUID v7 for databases
- ✓ Generate sortable ULID identifiers
- ✓ Bulk generation up to 50 at a time
Common Use Cases
- • Creating primary keys for database records
- • Generating unique identifiers for API resources
- • Assigning unique IDs in distributed systems
- • Creating correlation IDs for request tracing
Frequently Asked Questions
What is the difference between UUID v4 and v7?
UUID v4 is entirely random, while UUID v7 embeds a Unix timestamp in the first 48 bits. UUID v7 is better for database primary keys because it is naturally time-ordered, improving index performance.
What is a ULID?
ULID (Universally Unique Lexicographically Sortable Identifier) is a 128-bit identifier encoded as a 26-character Crockford Base32 string. It is time-ordered and sorts lexicographically.
Are generated UUIDs truly unique?
UUID v4 uses 122 random bits, giving approximately 5.3 × 10^36 possible values. The probability of a collision is astronomically low — effectively zero for practical purposes.
Which UUID version should I use?
Use UUID v7 for database primary keys (better index performance). Use UUID v4 when you need pure randomness with no time component. Use ULID when you need sortable IDs with a compact string representation.