UUID Generator
Generate random v4, time-based v1, and modern sortable v7 UUIDs instantly. Customize formatting, generate in bulk, and use them securely for database keys.
Our UUID Generator is a professional-grade tool for creating Version 1, 4, and the modern Version 7 Universally Unique Identifiers. Whether you need standard randomness (v4), time-based tracking (v1), or the latest lexicographically sortable identifiers (v7) for optimized database indexing, our entirely client-side generator provides high-entropy IDs instantly.
About this tool
Which UUID Version Should You Use?
While all UUIDs provide uniqueness, different versions are optimized for specific engineering challenges. Selecting the right version can significantly impact your application's performance and data structure legacy.
- Version 4 (Random): The industry standard for general unique IDs where randomness is key.
- Version 1 (Time-Based): Uses timestamps and node IDs—ideal for tracking when an ID was created.
- Version 7 (Modern/Sortable): Combines a Unix timestamp with random data, making it lexicographically sortable and perfect for database B-Tree indexing.
- Bulk Generation: Create up to 100 unique identifiers in a single click for testing and seeding.
The Advantage of UUID v7
UUID v7 is the modern successor for database primary keys. Because it starts with a timestamp, new IDs are naturally sorted by time, preventing fragmentation in database indexes and significantly improving insert performance compared to random v4 IDs. If you are integrating these into large datasets, you can validate your structures with our JSON Formatter or verify data integrity using our Hash Generator.
Security & Privacy
Generation happens 100% locally in your browser. For Version 4, we utilize the native `crypto.randomUUID()` API. For v1 and v7, our optimized implementation ensures strictly compliant bit-masks and total privacy—your IDs are never sent to a server.
How to Use UUID Generator
Select UUID Version
Choose between v1 (Time), v4 (Random), or v7 (Sortable) based on your system design requirements.
Choose Generation Mode
Switch between 'Single' for one-off IDs or 'Bulk' when you need a large list for seeding data.
Customize Formatting
Toggle hyphens, uppercase lettering, or even add curly braces '{}' to match specific platform requirements (like Windows/COM).
Generate and Refresh
New IDs are created instantly. Click the refresh icon or use the hotkeys to cycle through new sets of identifiers.
Export and Copy
Use the 'Copy All' button for the clipboard or download the entire list as a .txt file for larger datasets.
Common questions
What is the main difference between v1, v4, and v7?
v1 is based on time and hardware address (or random bits). v4 is entirely random. v7 is the most modern, combining a Unix timestamp with random bits to provide both uniqueness and time-based sortability.
Why is UUID v7 better for databases?
Because v7 starts with a timestamp, new IDs are 'greater' than older ones. This allows database B-Tree indexes to append data at the end rather than inserting randomly, which reduces disk I/O and improves performance.
Is UUID v4 still the standard?
Yes, v4 remains the most widely used version for things like session IDs or tracking pixels where time-based sorting isn't required and maximum randomness is preferred.
Are these UUIDs really unique?
Yes. The probability of a collision is so infinitesimally small that it is effectively zero for the life of any system. For v4/v7, there are 2^122 and 2^110 random bits respectively protecting against collisions.
When should I use v1?
Use v1 if you need to extract the generation timestamp from the UUID itself or when you need sequential-ish IDs in an environment where v7 support isn't yet standard.
What does 'lexicographically sortable' mean?
It means that when you sort the UUIDs as strings (A-Z), they will also be sorted in the order they were created. This is the 'superpower' of UUID v7.
Can I use these for secure tokens?
While UUIDs are unique, for high-security session tokens, consider using algorithms specifically designed for that purpose. For general identification, v4 and v7 are extremely secure.
Is my generation data private?
Absolutely. No network requests are made during generation. All IDs are computed locally in your browser's memory and are destroyed when you close the tab.
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