UUID Generator Online (v4)
Generate cryptographically random UUID (Universally Unique Identifier) version 4 identifiers online. Create single or bulk UUIDs with uppercase toggles, hyphen customizers, and one-click clipboard copying for databases, distributed systems, and testing.
Generator Options
How to Generate Random UUIDs
- 1
Select quantity
Choose how many UUIDs you need to generate (from 1 up to 100+ identifiers).
- 2
Configure casing and formatting
Toggle uppercase letters or adjust hyphen preferences according to your database requirements.
- 3
Generate and copy
Click Regenerate to refresh the list, then use Copy All or Download TXT to extract your identifiers.
UUID Generator Capabilities
RFC 4122 v4 Standard
Produces fully compliant Version 4 Universally Unique Identifiers with standard hexadecimal formatting.
Cryptographic Randomness
Powered by the browser Web Cryptography API (crypto.getRandomValues) to ensure unguessable, non-deterministic entropy.
Bulk Generation
Generate up to hundreds of UUIDs simultaneously for database seeding, migrations, and mock data suites.
Uppercase & Lowercase Options
Toggle between standard lowercase hex notation and uppercase format required by legacy database schemas.
Hyphen Separation Controls
Format standard 8-4-4-4-12 hyphenated strings or compact 32-character continuous hex strings.
Instant Download & Copy
Copy the entire batch to your clipboard with a single click or export them as a plain text (.txt) file.
What is a UUID (Universally Unique Identifier)?
A Universally Unique Identifier (UUID), also known as a Globally Unique Identifier (GUID) in Microsoft ecosystems, is a 128-bit number standardized by RFC 4122. Its design ensures that identifiers generated across distributed systems remain unique without requiring a central coordinating authority.
Version 4 UUIDs rely on cryptographic pseudorandom numbers. Out of 128 total bits, 122 bits represent pure randomness, yielding approximately 5.3 x 10^36 possible combinations. The probability of generating a duplicate UUID v4 is so negligible that for all practical software engineering purposes, collision risk is effectively zero.
Our online UUID generator uses the modern Web Cryptography API (crypto.getRandomValues) to ensure high-entropy, cryptographically strong random generation right inside your browser window.
Frequently Asked Questions
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