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Tools/UUID Generator

UUID Generator

Generate universally unique identifiers. Supports v1, v3, v4, v5, and v7.

100% client-side · no data stored
Bulk Generation
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About UUID versions
v4 - Random
Cryptographically random. Most common choice.
v7 - Time-ordered
Sortable by creation time. Ideal for database primary keys.
v1 - Time + MAC
Based on timestamp and node ID. Sortable but exposes timing.
v3 - Named (MD5)
Deterministic - same namespace + name gives same UUID using MD5.
v5 - Named (SHA-1)
Deterministic - like v3 but uses more secure SHA-1 hashing.

Free Online UUID Generator Tool for Developers

Welcome to the ultimate free online UUID generator. Whether you need a random UUID generator for web application session IDs, a time-ordered identifier for database primary keys, or a bulk batch of unique keys, our online UUID generator tool gives you instant access to standard RFC 4122 and RFC 9562 identifiers right in your browser.

Our online UUID generator supports version 1, version 3, version 4, version 5, and version 7 algorithms. Everything operates 100% client-side, ensuring your generated keys and data privacy are completely protected with zero server calls.

Understanding UUID Versions: Version 4 vs Version 7

UUID Generator v4 (Random UUIDs)

A uuid generator v4 creates pseudo-random identifiers containing 122 bits of cryptographic entropy. Known commonly as uuid generator 4, it is the most popular choice for general software engineering, API keys, and session identifiers. Using an online uuid generator version 4 guarantees negligible collision probability for distributed applications.

UUID Generator v7 (Time-Ordered UUIDs)

A uuid generator v7 combines a 48-bit Unix millisecond timestamp with 74 random bits. An online uuid generator version 7 provides time-sortable keys that prevent database B-Tree index fragmentation in systems like PostgreSQL, MySQL, and MongoDB while retaining total uniqueness when generated via our uuid generator online.

Why Use Our Free UUID Generator?

  • ✓Free UUID Generator with zero rate limits or paywalls.
  • ✓Supports random uuid generator v4 & time-sortable v7.
  • ✓Bulk generation of up to 1,000 keys per batch.
  • ✓100% private: Client-side execution in your browser.
  • ✓Custom formatting: Uppercase, hyphenless, or braces {...}.
  • ✓One-click clipboard copy and .txt file downloads.

Frequently Asked Questions (FAQ)

Everything you need to know about UUIDs, version differences, and our online UUID generator.

What is UUID?▼
A UUID (Universally Unique Identifier) is a 128-bit standardized reference number used in software development to uniquely identify information across computer systems without needing central coordination.
What does UUID stand for?▼
UUID stands for Universally Unique Identifier. It is standardized by the Internet Engineering Task Force (IETF) under RFC 4122 and RFC 9562.
What is a UUID used for?▼
UUIDs are widely used as database primary keys, session identifiers in web applications, transaction tracking IDs in microservice architectures, file upload identifiers, and distributed queue message keys.
How is the UUID generated?▼
UUIDs are generated using cryptographic pseudo-random number generators (v4), Unix millisecond timestamps combined with random sequence bits (v7), network MAC addresses with timestamps (v1), or deterministic hashing functions like MD5 (v3) and SHA-1 (v5).
Are UUID and GUID the same?▼
Yes, UUID (Universally Unique Identifier) and GUID (Globally Unique Identifier) refer to the exact same 128-bit identifier format. GUID is Microsoft's terminology, whereas IETF standards and Linux/Unix ecosystems use UUID.
Can UUID be duplicate?▼
While collisions are mathematically possible due to finite combinations, the probability of generating duplicate random UUIDs using a random uuid generator (v4) is 1 in 2122 (5.3 × 1036), making collisions virtually impossible in practice.
Which UUID version to use?▼
Use UUID v4 for standard random identifiers. Use UUID v7 for database primary keys where chronological sorting and fast indexing are required. Use v3 or v5 for deterministic namespace hashing.
What is the difference between UUID v4 and UUID v7?▼
UUID v4 is entirely pseudo-randomly generated, making it unpredictable but unsorted. UUID v7 places a 48-bit Unix timestamp at the start, making it time-ordered and optimal for database indexing while preserving cryptographic uniqueness.
Are the generated UUIDs saved on your servers?▼
No. Our free online UUID generator executes completely inside your local web browser. None of your generated UUIDs or settings are ever transmitted or saved to external servers.
Can I generate UUIDs in bulk?▼
Yes! You can instantly generate up to 1,000 UUIDs at once using our online uuid generator tool, copy them all to clipboard, or export them directly as a .txt file.