UUID Generator
Generate cryptographically secure UUID v4 identifiers. Generate up to 20 at once. Copy individually or all at once.
7a8e1de2-d829-4659-929e-5c8c0ee432f2UUID v4 — randomly generated using crypto.randomUUID(). Collision probability is astronomically low (1 in 5.3 × 10³⁶).
How to Use
- 1
Set quantity
Choose how many UUIDs to generate — 1, 5, 10, or 20 at once.
- 2
Click Generate
Click the Generate button to create cryptographically secure UUID v4 values.
- 3
Copy one or all
Click Copy next to a single UUID, or Copy All to get all of them at once.
How It Works
This tool generates cryptographically random UUID v4 identifiers using the browser's built-in crypto.randomUUID() function — up to 20 at once, ready to copy individually or all together.
What a UUID is for
A UUID (Universally Unique Identifier) is a 128-bit value designed to be unique across systems without needing a central coordinating authority — two different services generating UUIDs independently will, in practice, essentially never produce the same value by chance, which is exactly what makes them useful as database record IDs, API keys, or session identifiers across distributed systems.
Why v4 specifically
UUID v4 is generated using random or pseudo-random numbers with no embedded timestamp or hardware/device information — unlike some other UUID versions that encode a timestamp or a machine identifier. This makes v4 the most common choice when you just need a unique, non-guessable ID without any embedded metadata.
Examples
Generating a database primary key
Generating a UUID like `f47ac10b-58cc-4372-a567-0e02b2c3d479` to use as a unique record identifier in a database, instead of a sequential integer ID.
Generating multiple IDs for test data
Generating 20 UUIDs at once to quickly populate test fixtures or seed data that need unique identifiers.
Common Use Cases
- Generating unique database record IDs, especially for distributed systems without a central ID counter
- Creating unique API keys, session tokens, or tracking identifiers
- Populating test data or fixtures that need guaranteed-unique IDs
Tips
- UUIDs are unique enough for practical purposes but are not inherently secret or secure — don't use a raw UUID alone as an authentication credential without additional protection, since a leaked or guessed UUID (though astronomically unlikely to guess) could allow unauthorized access if it's the only barrier.
- If you need IDs that also sort chronologically (useful for database indexing performance), consider a timestamp-ordered ID format instead of UUID v4, which is intentionally unordered and random.
Frequently Asked Questions
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