Tool
UUID Generator
Generate UUID v4 or v1 instantly. Bulk generate up to 100 at once, toggle uppercase and hyphens, click any UUID to copy it.
Version
Quantity
1Generate UUIDs in three steps
No software to install. Works in any browser, on any device.
Choose UUID version
v4 for random IDs (most common), v1 for timestamp-ordered IDs.
Generate one or many
Generate 1 or up to 100 UUIDs at once for bulk needs.
Copy individual or full list
Click any UUID to copy it, or copy the entire batch at once.
Generated UUIDs
v4 and v1 support
v4 for random IDs (most common). v1 for timestamp-ordered IDs.
Bulk generation
Generate 1 or 100 UUIDs at once. Copy the full list instantly.
Cryptographically random
v4 uses crypto.getRandomValues. No collision risk in practice.
About the UUID Generator
A UUID (Universally Unique Identifier) is a 128-bit value used to uniquely identify objects in software systems. The format is always 32 hexadecimal digits in the pattern xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx, grouped as 8-4-4-4-12 characters separated by hyphens.
UUID v4 is the most widely used version. Each UUID v4 is generated from random numbers, making collisions statistically impossible — there are 2122 possible v4 UUIDs. This generator uses the browser's crypto.randomUUID() API for cryptographically random output.
UUID v1 is time-based. The timestamp of generation is encoded into the UUID, which means v1 UUIDs from the same machine are sortable by creation time. Useful in distributed databases like Cassandra.
Common uses: primary keys in databases, session tokens, correlation IDs in logs, idempotency keys for API requests, and file names that must not conflict across systems.
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Frequently Asked Questions
What is a UUID?
A 128-bit identifier formatted as xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx. Used as unique IDs for database records, API resources, session tokens, and anywhere globally unique identifiers are needed.
What's the difference between UUID v4 and v1?
v4 is entirely random — better for privacy and the most widely used version. v1 includes a timestamp and MAC address, making UUIDs time-ordered, which is useful in distributed databases like Cassandra.
Can two generated UUIDs ever be the same?
Theoretically yes, practically impossible. The probability of a collision for UUID v4 is 1 in 5.3×10^36. You would need to generate billions of UUIDs per second for millions of years to have a realistic chance.
UUID vs auto-increment ID — which should I use?
Use UUID when IDs need to be globally unique across multiple systems, generated on the client side without a database round-trip, or when you don't want to expose sequential record counts through your API.