Online UUID v1 v4 Bulk Generator - Toolzy

Generate UUIDs
Generated UUIDs
# UUID Action
UUID Inspector & Validator

Paste a UUID below to validate and analyze its structure.

Valid UUID Detected
Version
-
Variant
-
Structure Details
Generation Stats
  • Entropy Source Web Crypto API
  • Bits per UUID 128 bits
  • Unique Count 0
  • Collision Probability Negligible
UUID Reference
Common Versions
v1: Timestamp + MAC/Random node ID. Good for sorting.
v4: Fully random bits. Best for general purpose use.
Standards
RFC 4122: The standard defining UUID structure.

In-depth Guide to UUIDs

What is a UUID?

A Universally Unique Identifier (UUID) is a 128-bit number used to uniquely identify information in computer systems without significant central coordination. While the probability of two UUIDs being the same is not zero, it is so small that it is generally considered negligible for practical purposes.

UUID v1 vs. UUID v4

Version 1 is generated from a time-based value and a node ID (MAC address). This makes them sortable by time but can expose information about the machine that generated them. Version 4 is generated entirely from random bits, making them truly anonymous and perfect for most modern applications.

Database Performance Considerations

Using UUIDs as primary keys can have performance implications. Because standard v4 UUIDs are random, they can cause index fragmentation in B-tree based databases like MySQL. For better performance, consider using sortable UUIDs (like v1 or ULID) or storing them in binary format (16 bytes) rather than strings.

Security & Entropy

Toolzy uses the crypto.getRandomValues() API, which is the gold standard for browser-based randomness. This ensures that every UUID generated is unpredictable and secure for use in session identifiers, API keys, and secure record tracking.

What is a UUID Generator?

A UUID (Universally Unique Identifier) Generator is a tool used to create 128-bit numbers used to uniquely identify information in computer systems. These identifiers are designed to be unique across space and time, making them ideal for database keys, session identifiers, and transaction IDs.

Toolzy’s UUID Generator supports generating multiple UUIDs at once, with options for different versions (like v1 and v4) and formats. It ensures that every generated ID is compliant with RFC 4122 standards.

Frequently Asked Questions (FAQ)

UUID v1 is generated using the host network address and the current time, making it unique but potentially revealing information about the source. UUID v4 is generated using random numbers, making it completely unpredictable.

While the probability of generating two identical UUIDs is not zero, it is so infinitesimally small that for all practical purposes, they are considered unique.