UUID Generator
Generate cryptographically secure UUID v4, v1, and v7 identifiers in bulk with custom formatting options.
UUID Generator
Generate cryptographically secure RFC-compliant UUID v4 and v7 identifiers.
What is the UUID Generator?
The UUID Generator is a fast, cryptographically secure tool for generating Universally Unique Identifiers (UUIDs) conforming to RFC 4122 and RFC 9562 standards. A UUID is a 128-bit number used in software architecture to identify database records, API request IDs, microservice transactions, and session tokens without requiring a central authority.
Our generator supports all major UUID versions, including UUID v4 (random), UUID v1 (timestamp-based), and UUID v7 (time-ordered, highly optimized for database primary keys).
Supported UUID Versions
- UUID v4 (Random): Generated using Web Crypto API `crypto.getRandomValues()` for maximum entropy. 122 bits of randomness yields a collision probability so low it is statistically impossible.
- UUID v7 (Time-Ordered): Combines a 48-bit Unix epoch millisecond timestamp with 74 random bits. Highly recommended for database primary keys (PostgreSQL, MySQL, SQLite) to prevent index fragmentation.
- UUID v1 (Timestamp + Node): Uses MAC address/node representation and high-resolution time offset.
Key Features
- Bulk Generation: Generate up to 100 UUIDs in a single click.
- Formatting Options: Toggle Uppercase vs Lowercase, and include or strip hyphens (`-`).
- One-Click Copy & Export: Copy all generated UUIDs as raw text, CSV, or JSON array.
- Zero Collision Risk: Uses cryptographically secure pseudorandom number generators (CSPRNG).
How Does the UUID Generator Work?
1. Select UUID Version: Choose v4 (Random), v7 (Time-Ordered), or v1 (Timestamp).
2. Set Quantity: Choose how many UUIDs to generate (1 to 100).
3. Customize Format: Toggle Uppercase or Strip Hyphens if needed.
4. Click Generate: Instant generation directly in your browser.
5. Copy / Download: Copy all to clipboard or download as text file.
Formula & Calculation Method
UUID v4 Structure:
`xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx`
- 128 bits total: 122 random bits, 4 version bits (`4`), 2 variant bits (`y` is 8, 9, a, or b).
UUID v7 Structure:
`tttttttt-tttt-7xxx-yxxx-xxxxxxxxxxxx`
- First 48 bits = Unix timestamp in milliseconds.
- Version = `7`.
- Remaining 74 bits = CSPRNG random data.
Example Calculation
Sample UUID v4:
`f47ac10b-58cc-4372-a567-0e02b2c3d479`
- Version: 4 (Random)
- Variant: RFC 4122
- Entropy: $2^{122} \approx 5.3 \times 10^{36}$ possible combinations
Frequently Asked Questions
**UUID v4 Structure:** `xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx` - 128 bits total: 122 random bits, 4 version bits (`4`), 2 variant bits (`y` is 8, 9, a, or b). **UUID v7 Structure:** `tttttttt-tttt-7xxx-yxxx-xxxxxxxxxxxx` - First 48 bits = Unix timestamp in milliseconds. - Version = `7`. - Remaining 74 bits = CSPRNG random data.
Disclaimer: All developer utilities run 100% locally in your browser. None of your code, tokens, passwords, or input data are sent to or stored on remote servers.