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

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