Free UUID Generator & Validator — Generate UUID v1 & v4 Online

Generate UUIDs at scale, validate existing UUIDs, and copy in developer-friendly formats. Fast, private, and runs entirely in your browser.

Runs locally — no data leaves your browser
RFC 4122 compliantUses crypto.randomUUID100% browser-based
✨ Generates RFC 4122 UUIDs and validates version/variant

Why use this tool

Private by design
Everything runs locally in your browser. No uploads, no tracking of your UUIDs.
RFC 4122 compliant
Generate UUID v1/v4 and validate version + RFC 4122 variant instantly.
Bulk-friendly
Generate up to 1000 UUIDs and copy as plain text, JSON, or CSV.
Developer-ready
Includes copyable snippets for browser and Node.js usage.

UUID Validator

Validates format, version, and variant
Paste a UUID to validate
Count
v4: cryptographically random UUIDsMax 1000 per run

Generated UUIDs

Generate UUIDs to see results
Start generating UUIDs
Choose a UUID version, pick a count, and generate instantly. You can also validate any UUID above.
  • v4 random UUIDs (great default)
  • v1 timestamp-based UUIDs (useful for ordering)
  • Bulk copy as newline, JSON, or CSV
  • Validator shows version and RFC 4122 variant

Developer snippets

Browser (modern browsers)
crypto.randomUUID();
Node.js (v14+)
import { randomUUID } from "crypto";

randomUUID();

UUID information

  • v4: random UUIDs using Web Crypto where available
  • v1: timestamp-based UUIDs with random node + clock sequence (RFC 4122 variant)
  • Privacy: runs locally in your browser — no uploads

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Frequently Asked Questions

What is a UUID?

UUID stands for Universally Unique Identifier. It's a 128-bit identifier that is guaranteed to be unique across time and space. UUIDs are commonly used in software development for generating unique IDs for database records, API endpoints, and distributed systems.

What's the difference between UUID v4 and v1?

UUID v4 (random) generates completely random UUIDs using cryptographically secure random numbers. UUID v1 (timestamp-based) includes a timestamp and MAC address, making them sortable by creation time. Version 4 is more commonly used for privacy reasons.

How do I validate a UUID?

Paste your UUID into the validator field. The tool checks the UUID format and shows: version (v1/v4) and variant (RFC 4122). Try our JSON Formatter (/json-formatter) if you're embedding UUIDs in JSON.

What is the difference between GUID and UUID?

GUID is Microsoft's name for UUID. In practice, GUIDs are usually UUIDs. Most modern GUID/UUID values follow RFC 4122 and are compatible across systems.

Should I use UUID v1 or v4?

Use UUID v4 for most cases (random, privacy-friendly). Use UUID v1 if you need time-ordering properties (timestamp-based).

Can UUIDs collide (duplicate)?

In practice, UUID collisions are astronomically unlikely—especially for UUID v4 generated using cryptographically secure randomness. While no system can guarantee absolute uniqueness forever, UUIDs are designed to be effectively unique for real-world applications.

UUID vs auto-increment IDs — which is better?

Auto-increment IDs are small and fast but can leak record counts and require coordination across databases. UUIDs are globally unique across systems, great for distributed apps and offline-first sync, but are larger and may impact index performance unless you design your schema carefully. If you need random tokens instead, try Random String Generator (/random-string-generator) or API Key Generator (/api-key-generator).

Are UUIDs safe for databases?

Yes—UUIDs are widely used in production databases. For best performance, store them in efficient types (like UUID/BINARY), index thoughtfully, and consider v1/time-ordered UUIDs when write locality matters.

UUID format explained (RFC 4122)

A UUID is 128 bits shown as 32 hex characters in 5 groups: 8-4-4-4-12. The version is encoded in the 3rd group, and the variant (RFC 4122) is encoded in the 4th group.

How many UUIDs can I generate at once?

You can generate up to 1000 UUIDs at once. Use the presets (10, 50, 100) or the count slider/input, then generate. You can copy UUIDs individually or export them in bulk formats.

Is the UUID generator free to use?

Yes! Our UUID generator is 100% free with no registration required, no usage limits, and no hidden fees. You can generate as many UUIDs as you need.

Are my UUIDs stored or tracked?

No, all UUID generation happens locally in your browser using the Web Crypto API. We don't store, save, or have access to any UUIDs you generate. Your privacy is completely protected.

Can I use these UUIDs in production?

Yes! The UUIDs generated use the browser's cryptographically secure random number generator (crypto.randomUUID()), which meets RFC 4122 standards and is suitable for production use.