UUID Generator

RFC 4122 compliant — Bulk generation — Custom formats — Offline capable

Generated UUIDs

Click Generate to create UUIDs

UUID FormatStandard (36 chars)

Batch Settings

Generate

UUIDs at once

Common Use Cases

Database Keys

Primary keys for distributed systems

API Tokens

Secure session & request IDs

File Storage

Unique filenames for S3/CDN

Transaction IDs

Payment & audit trail tracking

Features

RFC 4122 Compliant

Standard UUID v4 format used worldwide

Bulk Generation

Create up to 100 UUIDs at once

Custom Formats

Prefix, suffix, length & casing options

Developer Friendly

Copy, download, or integrate via API

100% Offline

Works without internet connection

History Tracking

Access recently generated UUIDs

The Developer's Guide

The Universally Unique Identifier:
A 128-Bit Solution to Global Naming

📖 5 min read•Updated Dec 2024

In distributed systems, naming things is hard. How do you ensure two database nodes in different continents never generate the same primary key? How does a microservice create a correlation ID that won't collide with any other request, ever? The answer lies in a deceptively simple 128-bit number: the Universally Unique Identifier, or UUID.

First standardized by the Open Software Foundation in the 1990s and later formalized as RFC 4122, UUIDs solve the coordination problem by making collisions statistically impossible. With 2^122 possible values (approximately 5.3 × 10^36), you could generate a billion UUIDs per second for 100 years and still have less than a one-in-a-billion chance of a duplicate.

“After generating 1 billion UUIDs every second for the next 100 years, the probability of creating just one duplicate would be about 50%.”— RFC 4122 Probability Analysis

UUID Version 4: The Random Standard

This generator produces UUID version 4, which uses cryptographically secure random numbers. Unlike version 1 (which embeds MAC addresses and timestamps) or version 5 (which uses namespace hashing), v4 UUIDs reveal nothing about when or where they were created—ideal for privacy-conscious applications.

📐

UUID Anatomy

36 characters total
32 hexadecimal digits
4 hyphens (8-4-4-4-12)
Version in position 13

🎯

Best Practices

Store as VARCHAR(36)
Use binary(16) for indexes
Lowercase for consistency
Never parse for meaning

When to Use Compact Formats

The 32-character hyphen-free variant saves 4 bytes per identifier—significant when you're storing millions. It's also ideal for URLs, QR codes, and telemetry where every character counts. The 16-character short format sacrifices some uniqueness guarantee but works well for session tokens with built-in expiry.

🔧 Custom UUIDs with Semantic Prefixes

Many teams prefix UUIDs for routing and debugging: usr_a1b2c3d4 for users, ord_e5f6g7h8 for orders. This pattern makes log scanning trivial and helps engineers identify resource types at a glance—without any database lookup.

Whether you're seeding a development database, generating API keys, or building distributed transaction logs—this tool provides RFC-compliant, cryptographically random identifiers without any server roundtrip. All generation happens in your browser using the Web Crypto API. Your UUIDs never leave your device.

Guide

Architecture discipline with the UUID Generator

Reinforce system design reviews, data migrations, and audit evidence with reproducible UUID generation workflows.

3 min read790 wordsArchitectureData ModelingCompliance

Design reviews

When architects debate identifier strategies, they open the UUID Generator, switch between v4 and v7, and inspect the entropy or timestamp semantics live. Seeing the bytes in hex, base32, and base64 inside the FlowPanel helps product managers grasp why certain versions fit analytics or ordering requirements. Decisions documented alongside screenshots avoid future rehashing.

Migration rehearsals

Data engineers planning record migrations generate UUID batches to simulate surrogate keys. They paste the list into spreadsheets, verify uniqueness, and test ETL jobs before touching production. Because the tool never calls external APIs, even air-gapped environments can rely on it during rehearsal days.

Compliance evidence

Auditors often ask how IDs are created for sensitive workflows (loan files, medical records). Capture a short screencast of the generator preset, note the timestamp, and store the UUID sample plus hash. This shows regulators that identifiers meet randomness requirements without referencing proprietary code.

Developer onboarding

New hires practice using the generator to create fixture data for integration tests. They learn to copy UUIDs with or without hyphens, reducing mistakes when seeding databases. Pair the exercise with the Number Base Converter to show how the same identifier travels through logs, URLs, and QR codes.

Automation backlog

Platform teams can later embed UUID generation into CLI tools, but the UI remains the prototyping ground. Document which presets correspond to which services so when automation lands, engineers trust that the behavior matches what the FlowPanel demonstrated.

Culture of traceability

Encourage teams to reference the generator preset ID in design docs and tickets. Over time, you build a traceable link between architectural decisions and operational artifacts, making audits and incident investigations far smoother.

Frequently Asked Questions

What is a UUID?

A Universally Unique Identifier (UUID) is a 128-bit number used to identify information in computer systems. UUIDs are designed to be unique across space and time, without requiring a central coordination authority.

Are UUIDs truly unique?

While not mathematically guaranteed, the probability of collision is so astronomically low (1 in 2^122) that for all practical purposes, they can be considered unique. You could generate a billion per second for centuries and likely never see a duplicate.

What UUID version does this generate?

This tool generates UUID version 4, which uses cryptographically secure random numbers. V4 UUIDs don't encode any meaningful information like timestamps or MAC addresses, making them ideal for privacy.

Should I use UUIDs as database primary keys?

UUIDs work well as primary keys for distributed systems where coordination is impossible. However, for single-database applications, auto-increment IDs may offer better indexing performance. Consider UUIDv7 for time-ordered inserts.

Are UUIDs generated securely?

Yes. This tool uses crypto.getRandomValues(), a cryptographically secure pseudo-random number generator (CSPRNG) built into all modern browsers. It's the same source used for generating encryption keys.