UUID Generator
Generate up to 50,000 UUID v4 identifiers instantly in your browser. Free and private — no data sent to a server. No account needed.
Bulk UUID Generator
Instantly generate thousands of universally unique identifiers (v4) in your browser.
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier formatted as 8-4-4-4-12 hexadecimal characters — for example: 550e8400-e29b-41d4-a716-446655440000. UUIDs are designed to be globally unique without coordination between systems — any computer can generate one without checking a central server first.
Unlike sequential integer IDs (1, 2, 3), UUIDs can be generated independently across distributed systems, making them the standard choice for database primary keys, API resource identifiers, and session tokens in modern applications.
How to Use the UUID Generator
Set the quantity
Enter how many UUIDs you need — from 1 to 50,000. The default generates one UUID at a time.
Choose formatting options
Select uppercase, remove hyphens, or wrap values in quotes for use in code arrays or SQL INSERT statements.
Click Generate
All UUIDs are generated instantly in your browser using the native crypto.randomUUID() API — nothing is sent to a server.
Copy or download
Copy the results to your clipboard or download as a text file for database seed scripts, test fixtures, or configuration files.
Why Use UUID Version 4?
There are multiple versions of UUIDs, but Version 4 (v4) is the most common and is what this tool generates.
A Version 4 UUID is generated using completely random numbers. Because there are 2122 possible combinations (approximately 5.3 × 1036), the probability of generating the same UUID twice is functionally zero. You could generate a billion UUIDs every second for a hundred years, and the chance of a collision would still be astronomically small.
Who Is This For?
- ▸ Developers needing unique IDs for database records — generate a bulk list of UUIDs formatted for SQL INSERT statements or JSON seed files.
- ▸ Engineers building distributed systems or microservices who need resource identifiers that are unique across multiple services without coordination.
- ▸ Anyone who needs a random unique string for testing or configuration — API keys, session tokens, test fixture IDs, or placeholder identifiers in staging environments.
Key Benefits
- ✓ Runs entirely in your browser — uses the native
crypto.randomUUID()API; generated UUIDs are never stored or transmitted. - ✓ Free with no subscription — no account, no paywall, no usage limits.
- ✓ No account required — open the page and generate immediately.
- ✓ Bulk generation up to 50,000 — generate a full dataset of UUIDs in one click, formatted and ready to paste.
Common Use Cases
You are seeding a development database and need 500 unique IDs for test records. Generate them in bulk, download as a text file, and paste directly into your seed script.
You are designing a REST API and need to assign stable resource IDs to mock data before the database is set up. Generate UUIDs to use as placeholder IDs in your JSON fixtures.
You are building a feature that creates user-uploaded content and need a unique identifier for each uploaded file that cannot be guessed or iterated. UUID v4 provides cryptographically random IDs with no sequential pattern.
Frequently Asked Questions
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier formatted as 8-4-4-4-12 hexadecimal characters, for example: 550e8400-e29b-41d4-a716-446655440000. UUIDs are designed to be globally unique without coordination between systems — any computer can generate one without checking a central server first.
Is this tool free?
Yes — completely free with no account required. The UUID generator runs entirely in your browser using the native crypto.randomUUID() API. Generated UUIDs are never transmitted to or stored on a server.
What is the difference between UUID v4 and UUID v1?
UUID v4 is randomly generated — the most common type for databases and distributed systems. UUID v1 is time-based and includes the machine's MAC address in the identifier, making it less common today due to privacy concerns. For most use cases — database primary keys, API resource IDs, distributed systems — UUID v4 is the right choice.
Is a UUID truly unique?
In practice, yes. The probability of a UUID v4 collision is astronomically small — generating 1 billion UUIDs per second for 85 years gives only a 50% chance of a single collision. UUID v4 is universally treated as unique in production systems and is safe for use as primary keys and resource identifiers.
Is it safe to generate database keys here?
Yes. This tool uses the native crypto.randomUUID() API built directly into your web browser. The generation happens entirely on your machine. We do not track, log, or send any generated UUIDs to our servers, making it safe for production database seed scripts.
What is the difference between a UUID and a GUID?
From a technical standpoint, they are exactly the same thing. UUID is the standard term used across the broad tech industry. GUID (Globally Unique Identifier) is simply the term Microsoft coined and uses within their .NET and Windows ecosystems.
The tools and calculators provided on The Simple Toolbox are intended for educational and informational purposes only. They do not constitute financial, legal, tax, or professional advice. While we strive to keep calculations accurate, numbers are based on user inputs and standard assumptions that may not apply to your specific situation. Always consult with a certified professional (such as a CPA, financial advisor, or attorney) before making significant financial or business decisions.
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