BunchTool — Secure UUID Generator
Presets:
⚙️ Quantity & Formatting Controls
Formatting Toggles
📋 Generated UUID List Pending Generation
Related Tools

More free Developer tools


💻 Developer Tools

Secure UUID v4 Generator —
Generate Cryptographically Secure UUIDs Online

Our free Secure UUID Generator provides an in-browser generation tool to create RFC 4122 Version 4 random UUIDs / GUIDs. Uses the browser's native Web Crypto API (crypto.getRandomValues) to deliver cryptographically secure pseudo-random numbers suitable for database primary keys, session tokens, and API identifiers. Supports bulk batch generation from 1 to 500 UUIDs per run. Customize formatting options including letter case (lowercase vs uppercase), standard hyphenation vs compact strings, curly braces ({...}), URN prefix (urn:uuid:), and output styles (plain text list vs JSON array format). Select from pre-built presets and export results directly to uuids.txt or uuids.json. Executing 100% in local client-side JavaScript—your generated UUIDs are never transmitted to external servers.

Cryptographically secure Web Crypto API RFC 4122 v4 UUID generator
Bulk generation support from 1 to 500 UUIDs per batch
Custom formatting: Uppercase/Lowercase, Hyphens, Braces, URN prefix, JSON format
Pre-configured presets and 100% private in-browser file exports (.txt & .json)
🔑
RFC 4122 v4Standard Compliance
Web CryptoCSPRNG Secure
100% PrivateBrowser Computed
How It Works

Generate secure UUIDs in three steps

Step 1
⚙️
Select Quantity & Options

Choose the number of UUIDs (1-500), case (lowercase/uppercase), hyphens, braces, or JSON array format.

Step 2
🔑
Click Generate UUIDs

Click Generate UUIDs or select a preset (Single, Bulk 10, DB Batch 50, JSON Array).

Step 3
📋
Copy to Clipboard or Export

Copy all generated UUIDs to your clipboard or download uuids.txt / uuids.json.

Why BunchTool

Why use our free Secure UUID Generator?

🔒
Cryptographically Secure Randomness

Leverages the browser's Web Crypto API (crypto.getRandomValues / crypto.randomUUID) for production-grade CSPRNG entropy.

📦
Bulk Generation & Flexible Styling

Generate up to 500 UUIDs per run formatted with custom uppercase, hyphens, curly braces, URN prefixes, or JSON arrays.

100% Private In-Browser Generation

All UUID generation, string formatting, and file exports execute locally in your browser. Generated identifiers are never stored on any server.

FAQ

Frequently asked questions

What is a UUID v4 and how is it generated?
A Universally Unique Identifier Version 4 (UUID v4) is a 128-bit identifier generated using pseudo-random bytes per RFC 4122 standards. It consists of 32 hexadecimal digits separated by hyphens.
How secure are the UUIDs generated by this tool?
Extremely secure. Our generator utilizes the browser's Web Crypto API (crypto.getRandomValues or crypto.randomUUID), providing cryptographically secure pseudo-random number generation suitable for production database primary keys and auth tokens.
What is the probability of a UUID v4 collision occurring?
Virtually zero. With 122 random bits in a UUID v4, you would need to generate 1 billion UUIDs every second for approximately 85 years to have a 50% chance of a single collision.
What is the difference between UUID and GUID?
UUID (Universally Unique Identifier) is the open IETF standard (RFC 4122), while GUID (Globally Unique Identifier) is Microsoft's implementation. Functionally, they are identical 128-bit identifiers.
Are any generated UUIDs sent to or stored on a server?
No. All UUID generation, string formatting, and file exports execute 100% locally inside your web browser using client-side JavaScript.
Detailed Guide

Understanding RFC 4122 UUID v4 Bit Structure, Web Crypto CSPRNG & Collision Probability

A Universally Unique Identifier Version 4 (UUID v4) is a 128-bit number constructed per RFC 4122 specifications using 122 random bits combined with 6 fixed version (0100 for v4) and variant bits.

Randomness is derived directly from the browser's Web Crypto API (crypto.randomUUID() or crypto.getRandomValues()), ensuring cryptographically secure pseudo-random number generation (CSPRNG) for production primary keys.

With \(2^{122}\) (\(pprox 5.3 imes 10^{36}\)) possible unique combinations, the mathematical probability of a single UUID collision occurring in practical database systems is virtually zero.

Other Collections

Explore other useful categories

Explore 247 more free tools —
no login, no limits.

BunchTool covers PDF editing, text conversion, SEO analysis, calculators, design tools, unit converters and much more. All 100% free, all browser-based.

Browse All 247 tools →