UUID Generator
Generate random UUID v4 identifiers in bulk.
About This Tool
UUID Generator is a free online tool that generates RFC 4122 version 4 UUIDs — cryptographically random 128-bit identifiers — in bulk, directly in your browser. Generate 1 to 100 UUIDs at once, toggle uppercase formatting, and copy individually or all at once. No server, no account, no tracking.
UUIDs are generated using crypto.randomUUID(), the browser's native cryptographically secure UUID generation function. This guarantees statistical uniqueness without requiring a central registry or sequence — making UUID v4 ideal for distributed systems, offline-first applications, and any scenario where auto-increment database IDs are not practical or safe.
UUID Generator is used by software developers seeding test databases, generating correlation IDs for distributed logging, creating primary keys for database records, producing unique file or session identifiers, and testing UUID parsing and validation logic in their applications.
3c5aebbf-9f43-4838-a923-4d8b2da740cc855059f6-1d05-4716-8af7-b9f0e9a85668d7bcbd6a-c507-49e3-b3a0-90e6387eea3d8b408719-0b97-47dc-a97d-e05724e0252397b79398-2ed3-496d-9a4b-dbaad3989b44How to Use
- 1
Set the number of UUIDs you want to generate (1 to 100).
- 2
Toggle uppercase format if needed.
- 3
Click Generate and copy individual UUIDs or use Copy All to copy them all at once.
- 4
Paste the UUIDs directly into your database migration scripts, test fixtures, or configuration files.
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Re-generate for a fresh set of unique identifiers whenever you need them.
Features
Bulk Generation
Generate up to 100 UUID v4 identifiers at once for use in databases, code, or testing.
Cryptographically Secure
Uses crypto.randomUUID() for cryptographically random, RFC 4122-compliant UUID v4 values.
Uppercase Option
Toggle uppercase format for UUIDs to match your project's naming conventions.
Copy All
Copy all generated UUIDs to the clipboard at once with a single button click.
Common use cases
- ›Seed database migrations with unique primary key values for test records or fixtures.
- ›Generate correlation IDs for distributed system logging and tracing.
- ›Create unique identifiers for user sessions, API request tracking, or file uploads.
- ›Produce bulk UUIDs for test data generation in unit tests or integration test setups.
Read our guide
UUID Generator — Complete Guide →FAQ
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier that is practically guaranteed to be unique.
How are UUIDs generated?
Using crypto.randomUUID() which provides cryptographically secure random UUIDs.
What is the difference between UUID v4 and other versions?
UUID v4 is randomly generated (122 random bits) and requires no namespace or time input, making it the simplest and most widely used version for generating unique identifiers in applications.
Can the same UUID be generated twice?
Theoretically yes, but the probability is astronomically small. With 2^122 possible UUIDs, you would need to generate quintillions of UUIDs before expecting a collision.
Should I use uppercase or lowercase UUIDs?
Both are valid per RFC 4122. Lowercase is more common in web APIs and databases. Use uppercase if your system or existing data requires it. The format does not affect uniqueness.