UUID / GUID Generator

Generate random RFC4122 Version-4 UUIDs / GUIDs individually or in bulk batches with copy & download.

How many UUIDs?

Include Hyphens (-) Uppercase Wrap in { braces }

Generated UUIDs / GUIDs:

How to Use this Tool

1. Select your preferred UUID version (Version 4 Random or Version 1 Timestamp). 2. Choose uppercase or lowercase format, and specify quantity if generating multiple IDs. 3. Click 'Generate UUIDs' to produce RFC-4122 compliant universally unique identifiers.

Mathematical Formula & Explanation

RFC 4122 Version 4 UUID Specification: Format: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx (36 characters including 4 hyphens) 1. 128 bits generated using cryptographically secure random number generator. 2. Version Bit Assignment: Set bits 12 through 15 of time_hi_and_version to 0100 (binary for 4). 3. Variant Bit Assignment: Set bits 6 and 7 of clock_seq_hi_and_reserved to 01 (binary for RFC 4122 variant, yielding hex values 8, 9, a, or b for 'y'). Total Unique UUIDv4 Combinations = 2^122 ≈ 5.3 × 10^36.

About UUID / GUID Generator

The Free Online UUID & GUID Generator produces RFC 4122 compliant universally unique identifiers (UUIDs) and globally unique identifiers (GUIDs) using cryptographically secure pseudo-random numbers.

A UUID is a 128-bit label used in software systems to uniquely identify records across distributed databases without requiring a central coordinating authority. The probability of generating two duplicate Version 4 UUIDs is practically zero (1 in 2.71 quintillion).

Key Features & Capabilities:
• Version 4 (Random) Compliance: Standard 128-bit random UUID format utilized across modern software engineering.
• Case Formatting: Generate UUIDs in standard lowercase or uppercase format.
• Bulk Generation Mode: Generate multiple unique UUIDs at once for database seeding and batch testing.
• Cryptographically Secure: Uses `crypto.getRandomValues()` to guarantee true statistical entropy and unpredictability.
• Instant Clipboard Copy: Single-click copying for individual identifiers or complete batch lists.

Common Applications:
1. Database Primary Keys: Assign unique, non-sequential IDs in distributed databases (PostgreSQL, MongoDB, Cassandra).
2. Distributed Tracing: Tag microservices API requests with correlation IDs and trace tokens for observability.
3. Session & Token Management: Generate unguessable session IDs, CSRF tokens, and download verification links.

Frequently Asked Questions (FAQs)

4 Questions

Everything you need to know about UUID / GUID Generator and how it works.

Is UUID / GUID Generator completely free to use?

Yes, UUID / GUID Generator is 100% free with unlimited calculations. There are no registration requirements, no paywalls, and no hidden subscriptions.

Is my data private and secure while using UUID / GUID Generator?

Yes, your privacy is fully protected. All calculations run strictly client-side within your web browser. None of your input data is stored or logged on our web servers.

Can I use UUID / GUID Generator on my mobile smartphone or tablet?

Yes, this tool is fully responsive and optimized for mobile devices, tablets, and desktop computers. You can also install it as a Progressive Web App (PWA) directly to your home screen.

How accurate are the results provided by UUID / GUID Generator?

All calculations and transformations follow standard mathematical algorithms and authoritative standards to provide real-time, high-precision results.