Free UUID / GUID Generator Online
Generate universally unique identifiers (UUID) in one click. Version 4 (random) or version 7 (time-ordered). Batch generation up to 100 UUIDs. Free, no sign-up — everything happens in your browser.
🔒 Generated using crypto.getRandomValues() — nothing leaves your browser.
100% secure
Your files are never shared
Ultra-fast
Processing in seconds
Privacy
Automatic deletion after 1h
How to generate UUIDs
Choose the version
Select UUID v4 (random — best for general use) or UUID v7 (time-ordered — best for database keys).
Set quantity and format
Choose how many UUIDs to generate (1-100) and your preferred format: with dashes, without dashes, uppercase or lowercase.
Generate and copy
Click Generate, then use Copy All to copy all UUIDs to your clipboard at once.
Understanding UUID versions
UUID v1 combines a timestamp with the device's MAC address. While it guarantees uniqueness, it exposes the creator's network identity and creation time, raising privacy concerns. It's rarely used in modern applications.
UUID v4 is the most widely used version. All 122 bits (excluding 6 version/variant bits) are randomly generated using a cryptographically secure random number generator. It's simple, private, and has an astronomically low collision probability.
UUID v7 (RFC 9562, 2024) is the newest standard. It places a Unix timestamp in the most significant bits, followed by random data. This makes v7 UUIDs naturally sortable by creation time — a major advantage for database indexing. If you're choosing a UUID version for a new project, v7 is the recommended choice for database primary keys.
UUIDs as database primary keys
Using UUIDs as primary keys offers several advantages: no collisions when merging data from multiple sources, no need for a centralized ID generator, no sequential IDs that reveal business metrics (order count, user count), and the ability to generate IDs on the client side before inserting into the database.
The main drawbacks are size (16 bytes vs 4 bytes for a 32-bit integer) and, for v4, random distribution that can cause B-tree index fragmentation and slower inserts. UUID v7 solves the fragmentation problem by being time-ordered, making inserts sequential and index-friendly.
Anatomy of a UUID
A UUID is displayed as 32 hexadecimal characters in five groups separated by dashes: 8-4-4-4-12. For example: 550e8400-e29b-41d4-a716-446655440000. The third group's first character indicates the version (4 for v4, 7 for v7). The fourth group's first character indicates the variant (8, 9, a, or b for the standard RFC 4122 variant).
The total is 128 bits (16 bytes). In v4, 122 of these bits are random. In v7, the first 48 bits are a millisecond-precision Unix timestamp, 4 bits are the version, 2 bits are the variant, and the remaining 74 bits are random.
Your privacy, our priority
AwesomeToolkit generates UUIDs entirely in your browser. For v4, we use crypto.randomUUID() when available, falling back to crypto.getRandomValues(). For v7, we combine Date.now() with crypto.getRandomValues().
No UUID, no configuration, no data of any kind is ever sent to our servers. The tool works completely offline once the page is loaded.
Free UUID / GUID Generator Online — Frequently asked questions
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit standardized identifier (RFC 4122) used to uniquely identify resources in computer systems. It consists of 32 hexadecimal characters separated by dashes (e.g., 550e8400-e29b-41d4-a716-446655440000). It's also called GUID (Globally Unique Identifier) in the Microsoft ecosystem.
What's the difference between UUID v4 and v7?
UUID v4 is entirely random — every bit (except version bits) is randomly generated. UUID v7 embeds a timestamp in the first bits, making it chronologically sortable. V7 is recommended for database primary keys as it improves indexing performance.
Are the generated UUIDs truly unique?
In practice, yes. The probability of generating two identical UUID v4s is about 1 in 2^122 (5.3 × 10^36). To put this in perspective, you would need to generate 1 billion UUIDs per second for 85 years to have a 50% chance of a collision.
UUID or GUID — what's the difference?
No functional difference. GUID (Globally Unique Identifier) is the term used by Microsoft, while UUID is the standard term (RFC 4122). Both refer to the same 128-bit identifier format.
Are my UUIDs sent to a server?
No. UUIDs are generated entirely in your browser using the Web Crypto API. No data passes through our servers.
When are UUIDs used?
UUIDs are used as database primary keys, session identifiers, API identifiers, unique file names, transaction identifiers, and in any system where a unique identifier is needed without central coordination.