Are GUIDs / UUIDs truly unique?

Yes, for all practical purposes. UUID v4 has 122 random bits, producing 5.3 × 10³⁶ possible values. Even generating millions of UUIDs per second across thousands of systems, the probability of a collision is negligibly small.

Is UUID v4 safe to use as a secret token?

UUID v4 is cryptographically random but was not designed to be a secret. For authentication tokens, API keys, or session tokens, use a dedicated token generation library. UUIDs are ideal as public, non-sensitive identifiers.

Can I generate multiple UUIDs at once?

Yes. Set the count field to any number between 1 and 1,000 and click Generate. All UUIDs are produced instantly and displayed one per line, ready to copy as a batch.

Free UUID v4 Generator (GUID Generator)

Q: What is the difference between a GUID and a UUID?

GUID (Globally Unique Identifier) is Microsoft's term for the same standard as UUID (Universally Unique Identifier). Both refer to the 128-bit identifier format defined in RFC 4122. They are interchangeable in practice.

Q: Is this GUID generator secure and private?

Completely. Generation uses the browser's native crypto.randomUUID() API backed by a CSPRNG (cryptographically secure pseudo-random number generator). No data is transmitted to any server, and no analytics or logs are collected for the generated values.

Generate random UUID v4 (RFC 4122 compliant) GUIDs instantly online. Bulk generate up to 1,000 unique UUIDs with multiple format options, one-click copy, and download as TXT or CSV.

GenerateUUIDs

Format Options

UppercaseNo hyphensBraces{ }Parentheses( )

Result

fb1df1d9-2be2-4dc1-813d-9b68b13a5292

PrivateProcessed LocallyNo Uploads

All processing happens in your browser No data is stored or sent to any server

What is a UUID / GUID?

A UUID (Universally Unique Identifier), also called a GUID (Globally Unique Identifier), is a 128-bit standardized value used to create unique identifiers across all computers and systems without requiring a central authority. The UUID standard is defined in RFC 4122. GUID is Microsoft's equivalent term for the same concept.

A UUID v4 example looks like this: 550e8400-e29b-41d4-a716-446655440000. It consists of 32 hexadecimal digits in five groups (8-4-4-4-12) separated by hyphens. With 2¹²⁸ possible values (~340 undecillion), the probability of collision between randomly generated UUIDs is negligibly small and can be safely ignored in all real-world applications.

Common Developer Use Cases

UUID v4 generators are essential in modern development for creating unique identifiers without requiring a central authority. This bulk UUID generator is ideal for developers building distributed systems, APIs, and databases at scale.

Databases

Primary keys that safely merge data from multiple sources without ID clashes.

REST APIs

Expose resource identifiers without revealing sequential counts or internal structure.

Distributed Systems

Generate IDs on any node without network coordination.

File Storage & Testing

Avoid filename collisions on cloud storage. Create unique test fixtures without a database.

What is UUID v4?

RFC 4122 defines five UUID versions. This free UUID v4 generator creates random UUIDs, which are the most popular choice for modern applications:

UUID v4 - Random (used by this tool)

Generated entirely from cryptographically secure random numbers using RFC 4122 standards. Contains no traceable information (timestamp or machine ID). This is the most widely adopted version for general-purpose unique identifiers in modern applications and APIs.

UUID v1 - Time-based

Built from the current timestamp and MAC address. Encodes when and where it was created - useful for sorting but risky for privacy. Less common in new applications than random UUID v4 generation.

GUID vs UUID: What's the Difference?

There is no technical difference. GUID (Globally Unique Identifier) is Microsoft's terminology for UUID (Universally Unique Identifier). Both refer to the same 128-bit identifier format standardized in RFC 4122. When someone asks you to generate a GUID, they want a UUID - typically a random UUID v4.

Microsoft uses "GUID" in .NET, SQL Server, and Windows systems, while other platforms and standards use "UUID." This free GUID generator produces RFC 4122-compliant UUIDs that work seamlessly in both Microsoft and non-Microsoft environments.

UUID Format Examples

This bulk UUID generator supports multiple output formats:

Standard:550e8400-e29b-41d4-a716-446655440000

Uppercase:550E8400-E29B-41D4-A716-446655440000

No hyphens:550e8400e29b41d4a716446655440000

With braces:{550e8400-e29b-41d4-a716-446655440000}

With parentheses:(550e8400-e29b-41d4-a716-446655440000)

Is This UUID Generator Secure?

Yes, completely secure and private. This random UUID v4 generator runs 100% in your browser using the crypto.randomUUID() Web API - part of the W3C Web Cryptography standard. Every generated UUID is created locally on your device using a CSPRNG (cryptographically secure pseudo-random number generator). No UUIDs, personal data, or logs are ever sent to any server.

RFC 4122 Compliant: All UUIDs generated meet the cryptographic randomness requirements of RFC 4122 standards. Generation is instant for any count up to 1,000 because all processing runs on your CPU. This bulk GUID generator also works offline after the page loads.

Features

Batch generation

Generate 1 to 1,000 GUIDs in a single click.

Five output formats

Standard, uppercase, no hyphens, braces, or parentheses.

One-click copy

Copy all generated UUIDs to clipboard instantly.

100% private & offline

UUIDs never leave your browser. Works offline after first load.

Related guides

GUID vs UUID Explained

GUID and UUID usually describe the same 128-bit identifier. Learn the terminology, UUID v4 format choices, common mistakes, and when to use each term.

Read guide ->

How to Generate a GUID Online

Generate random UUID v4 GUIDs online with UseBoldTools: choose count, format output, copy values, or download TXT and CSV files from your browser.