UUID Generator
UUID v4Generate cryptographically random UUID v4 values instantly. Single or bulk, copy or download.
max 100
What is a UUID?
A UUID (Universally Unique Identifier), also known as a GUID (Globally Unique Identifier), is a 128-bit value formatted as 32 hexadecimal characters in five groups separated by hyphens: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx. UUIDs are designed to be globally unique without requiring a central authority.
Common Use Cases for UUIDs
- Database primary keys in distributed systems
- Session tokens and authentication identifiers
- Unique filenames in cloud storage (S3, GCS)
- API correlation IDs for request tracing
- Feature flag and experiment IDs
Frequently Asked Questions
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit label used to uniquely identify information in computer systems. The probability of generating two identical UUIDs is negligibly small, making them ideal for database keys, session IDs, and distributed system identifiers.
What is UUID v4?
UUID v4 is a randomly generated UUID. Unlike v1 (time-based) or v3/v5 (name-based), v4 uses random numbers for all bits except two version indicator bits. It is the most commonly used UUID version for general-purpose unique ID generation.
Are the generated UUIDs truly unique?
Yes. This tool uses the browser's native crypto.randomUUID() function, which uses a cryptographically secure random number generator. The probability of collision is so astronomically low it is considered safe to treat these as globally unique.
Can I use these UUIDs as database primary keys?
Yes. UUID v4 values are commonly used as primary keys in PostgreSQL, MySQL, MongoDB, and DynamoDB. They allow records to be created across distributed systems without coordination.
Is there a limit on how many UUIDs I can generate?
This tool supports generating up to 100 UUIDs at once. For bulk generation beyond that, click Generate multiple times and download each batch as a text file.