UUID Generator
Generate universally unique identifiers (UUIDs) with support for v1, v4, and v5 versions with timestamp and name-based generation. Perfect for distributed systems, database keys, and unique identification requirements.
Random UUID using secure random numbers
How it works:
- • Version 1: Timestamp-based UUID with MAC address for chronological ordering
- • Version 4: Cryptographically secure random UUID using Web Crypto API
- • Version 5: Namespace-based UUID with SHA-1 hash for deterministic generation
- • All UUIDs are 128-bit identifiers following RFC 4122 specification
Complete Guide: UUID Generator
Everything you need to know about using this tool effectively
The UUID Generator creates version 4 universally unique identifiers (UUIDs) in the standard 8-4-4-4-12 format (e.g., 550e8400-e29b-41d4-a716-446655440000). UUID v4 uses random bits for the majority of the identifier, making collisions astronomically unlikely. All processing happens in the browser using the crypto.randomUUID API.
This tool calls crypto.randomUUID to generate RFC 4122 version 4 UUIDs. Each UUID is a 128-bit number formatted as a 36-character string with hyphens. The tool can generate single UUIDs or batches.
Generating database primary keys
Create UUIDs as unique identifiers for database records.
Creating API request IDs
Generate unique IDs for tracking API requests across services.
Building session tokens
Create unique session identifiers for web applications.
Naming files uniquely
Use UUIDs as file names to prevent collisions in storage systems.
Set count
Choose how many UUIDs to generate.
Generate
Click Generate to create the UUIDs.
Copy the UUID
Click on any UUID to copy it.
Download all
Download all generated UUIDs as a text file.
UUID v4 has 122 bits of randomness, making collisions practically impossible.
Use lowercase for consistency in databases and code.
UUIDs are 36 characters long including hyphens.
Do not truncate UUIDs. The full length is needed for uniqueness.
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information. UUID v4 uses random bits, making each generated UUID virtually guaranteed to be unique.
What is the format?
8-4-4-4-12 hexadecimal digits separated by hyphens: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx.
Is my data sent to a server?
No. All generation happens in your browser using crypto.randomUUID. Nothing is transmitted.
How many UUIDs can I generate?
There is no practical limit. Generate as many as you need.
Are collisions possible?
The probability of generating two identical UUID v4s is approximately 1 in 2^122, which is effectively zero.