Generate random UUID v4 identifiers instantly. Batch generate up to 100 UUIDs in multiple formats. Free online UUID generator tool.
What Is UUID Generator Online?
A UUID (Universally Unique Identifier) is a 128-bit value formatted as a 32-character hexadecimal string with hyphens (e.g. 550e8400-e29b-41d4-a716-446655440000). UUIDs are designed to be unique across all devices and time without requiring a central authority to issue them.
Version 4 UUIDs, which this tool generates, use cryptographically random numbers. The probability of generating two identical v4 UUIDs is so low that you could generate one billion UUIDs per second for 85 years before having a 50% chance of a single collision. This makes them ideal for database primary keys, API identifiers and distributed systems where coordinated ID generation is impractical.
How to Use This Tool
Click "Generate" to create a new random UUID v4.
The UUID appears in the standard 8-4-4-4-12 format.
Click "Copy" to copy the UUID to your clipboard.
Premium users can batch-generate multiple UUIDs and choose alternative formats (uppercase, no dashes).
Tips & Best Practices
UUIDs are not sequential — do not use them where ordering matters unless you use UUID v7 (timestamp-based).
For database primary keys, consider whether a UUID or an auto-incrementing integer is more appropriate for your use case.
UUID v4 is random and has no embedded information — it cannot be traced back to a device or time.
Store UUIDs as 16 bytes (binary) in databases rather than 36-character strings to save space.
Common Use Cases
Generating unique primary keys for database records.
Creating unique identifiers for API resources in distributed systems.
Generating session IDs or correlation IDs for logging and tracing.
Producing unique file names to avoid collisions in storage systems.
Creating test data with realistic identifiers.
Frequently Asked Questions
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier that is practically unique across all devices and time. UUID v4 uses random numbers, making collisions statistically near-impossible.
How many UUIDs can I generate at once?
Free users can batch-generate up to 10 UUIDs at once in standard, uppercase, lowercase or no-hyphens format. Premium raises the batch size to 100 and adds saved history plus .txt export.