Free UUID Generator Online - Generate UUID v4, v1, v7 Instantly
Create random UUID version 4 (v4) identifiers online instantly with our UUID Generator. Ideal for developers, database administrators, and API designers who need globally unique IDs without collisions. Fast, secure, and browser-based—no signup or installation required.
Universally Unique Identifier • Version 4 (Random)
About This Tool
Learn what makes this tool special
UUID v4 is the most popular version, using 122 bits of cryptographic randomness with collision probability of 1 in 2^122. UUID v1 includes timestamp and MAC address for uniqueness. UUID v7 (RFC 9562) combines timestamp with randomness for database-friendly sorting.
Perfect for developers working with PostgreSQL, MySQL, MongoDB, distributed systems, microservices, API request IDs, session tokens, and database primary keys. All generation happens in your browser using window.crypto.getRandomValues - zero server storage, complete privacy.
Use Cases: Database primary keys, API correlation IDs, session management, distributed logging, content addressing, and any scenario requiring guaranteed uniqueness without central coordination.
Technical Details: RFC 4122/9562 compliant, 128-bit identifiers, 36-character string format (xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx), version and variant bits properly set.
Key Features
What makes this tool special
- Generate unlimited UUID v4 identifiers for free
- Cryptographically secure random generation
- Extremely low collision probability (1 in 2^122)
- Generate single UUIDs or bulk lists
- Copy UUIDs to clipboard with one click
- RFC 4122 compliant UUID v4 format
- 100% browser-based processing - no uploads
- No data storage or server communication
- Mobile-friendly responsive design
- Instant generation with no delays
- Batch generation for multiple identifiers
- Proper UUID formatting and validation
- Support for database primary keys
- Perfect for APIs and distributed systems
- Multiple UUID versions (v1, v4, v7)
- Time-ordered UUID v7 for databases
- Time-based UUID v1 generation
- Extract timestamps from v7 UUIDs
- GUID (Microsoft) format support
- Binary UUID representation
- UUID validation and parsing
- Cross-platform compatibility
- Zero dependencies, pure JavaScript
Quick Guide
Master this tool in seconds
- 1Click 'Generate UUID' to create a new unique identifier
- 2Use 'Generate Multiple' to create bulk UUID lists
- 3Copy individual UUIDs using the copy button
- 4Select and copy multiple UUIDs as needed
- 5Use generated UUIDs in your applications, databases, or APIs
Common Questions
Everything you need to know
Q.What is a UUID and why use it?
UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems, perfect for databases and distributed applications.
Q.How unique are the generated UUIDs?
Extremely unique! UUID v4 has a collision probability of approximately 1 in 2^122, making duplicates virtually impossible.
Q.Is this UUID generator secure?
Yes, uses cryptographically secure random generation methods, same as professional development tools.
Q.Are generated UUIDs stored anywhere?
No, all UUIDs are generated locally in your browser and never stored, logged, or transmitted.
Q.Can I generate multiple UUIDs at once?
Yes, you can generate bulk lists of UUIDs for populating databases or testing applications.
Q.What format are the UUIDs in?
Standard RFC 4122 UUID v4 format: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
Q.Does it work offline?
Yes, once loaded, the UUID generator works completely offline with no internet connection required.
Q.Can I use these UUIDs in my database?
Absolutely! UUIDs are perfect for primary keys in databases, especially distributed systems.
Q.What's the difference between UUID and GUID?
GUID (Globally Unique Identifier) is Microsoft's name for UUID. They are functionally identical and follow the same RFC 4122 specification.
Q.Which UUID version should I use?
Use v4 for general purposes, v7 for database primary keys (sortable), v1 for time-based uniqueness with hardware identity.
Q.What is UUID v7 and why is it better for databases?
UUID v7 embeds a timestamp in the most significant bits, making UUIDs naturally sortable by creation time, improving database index performance.
Q.Can UUIDs collide?
Theoretically yes, but practically impossible. With 122 bits of randomness in v4, you'd need to generate 2^61 UUIDs to have a 50% collision chance.
Q.How do I store UUIDs in PostgreSQL?
Use PostgreSQL's native 'uuid' type for optimal storage and indexing. It stores as 16 bytes internally while accepting standard string format.
Q.Should I use UUIDs or auto-increment IDs?
Use UUIDs for distributed systems, global uniqueness, and client-side generation. Use auto-increment for single databases with human-readable IDs.
Q.How do I generate UUIDs in JavaScript?
Use crypto.randomUUID() (modern browsers) or libraries like uuid. Our tool uses the same cryptographically secure method.
Q.What are the benefits of UUID v7 over v4?
v7 UUIDs are sortable by time, improving database index performance and allowing efficient time-based queries without separate timestamp columns.
Q.Can I extract timestamps from UUID v7?
Yes, v7 UUIDs embed Unix millisecond timestamps that can be extracted for auditing, sorting, or business logic purposes.
Q.Are UUIDs slower than auto-increment IDs?
Slightly, due to larger size (16 vs 4-8 bytes), but the uniqueness benefits outweigh performance costs in distributed systems.
Q.How do UUIDs prevent database conflicts?
UUIDs can be generated independently on any system without coordination, eliminating the need for central ID servers in distributed architectures.
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