UUID v4 Generator Online — Generate Random UUIDs Free
Generate random UUIDs (v4) for your applications.
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UUID v4 (random) is generated using cryptographically secure random numbers. Each UUID is 128 bits (36 characters including hyphens) and has a near-zero probability of collision.
Privacy first: This tool runs entirely in your browser. Your data never leaves your device.
Generate one or many cryptographically random UUID v4 values in a single click. UUIDs are generated entirely in your browser using the Web Crypto API, ensuring true randomness without any server involvement. Copy individual UUIDs or download a batch.
How to Use UUID Generator
- Set the quantity: Choose how many UUIDs you want to generate (1 to 100 or more).
- Generate: Click "Generate" to produce the requested number of UUIDs.
- Copy or download: Click the copy button next to any UUID, or download all generated UUIDs as a text file.
Features
- Generates cryptographically random UUID v4 values
- Generate one or hundreds in a single click
- One-click copy for each UUID
- Download bulk UUIDs as a plain text file
- Uses the Web Crypto API for true randomness
- Free with no account required
Common Use Cases
Developers use UUID generators when seeding databases, creating unique identifiers for records in distributed systems, generating session tokens, and testing applications that require unique IDs as test data.
Frequently Asked Questions
- What is a UUID?
- A UUID (Universally Unique Identifier) is a 128-bit label used to uniquely identify objects in computer systems. The v4 variant is randomly generated and has an extremely low probability of collision.
- Are the generated UUIDs truly random?
- Yes. The tool uses the Web Crypto API's getRandomValues() function, which provides cryptographically strong random numbers.
- Are my UUIDs sent to a server?
- No. All UUIDs are generated entirely in your browser. Nothing is sent to or stored on any server.
- What is UUID v4 vs v1 or v5?
- UUID v4 is randomly generated. UUID v1 is based on timestamp and MAC address. UUID v5 is based on a namespace and name using SHA-1. v4 is the most widely used in modern applications.