🆔 Bulk UUID, NanoID & MAC Generator
Generate up to 5,000 random or time-ordered identifiers in memory with sub-50ms execution, custom delimiters, and one-click bulk export.
crypto.getRandomValues). No generated IDs are ever stored, cached, or transmitted over the network.Why Time-Sorted UUIDv7 Is Replacing UUIDv4
For over two decades, UUIDv4 has been the default standard for distributed primary keys. However, because UUIDv4 is 100% random, appending new records scatters writes unpredictably across database B-tree index pages. This causes page thrashing, bloated indexes, and degraded write throughput in high-volume systems like PostgreSQL, MySQL, and DynamoDB.
UUIDv4 (Random)
- • 122 bits of pure pseudorandom entropy.
- • No natural time-based ordering or sorting.
- • Causes B-Tree index fragmentation and cache misses.
- • Ideal when timestamps must remain completely private.
UUIDv7 (RFC 9562 Monotonic)
- • 48-bit Unix timestamp millisecond prefix + 74 random bits.
- • Naturally sorts in chronological ascending order.
- • Up to 10x faster database insertion throughput.
- • Zero coordination required between distributed nodes.
Frequently asked questions
What is the difference between UUIDv4 and UUIDv7?
UUIDv4 is completely pseudo-random, meaning consecutive IDs have no chronological order. UUIDv7 (standardized in RFC 9562) embeds a 48-bit millisecond Unix timestamp in the high bits followed by cryptographically random bits, making it naturally time-ordered and sortable.
Why is UUIDv7 superior for database primary keys?
Random UUIDv4 keys cause severe B-tree index fragmentation and page splits in database engines like PostgreSQL, MySQL, and SQLite. UUIDv7 provides sequential monotonic ordering, delivering up to 10x faster insert performance and optimal caching while preventing collisions.
How does the MAC address generator ensure valid addresses?
Generated MAC addresses enforce the Unicast bit (least significant bit of first octet is 0) and the Locally Administered bit (second least significant bit is 1). This guarantees generated MACs will not collide with IEEE-assigned hardware OUIs on physical network interfaces.
Can I generate thousands of IDs without freezing the browser?
Yes. The generation algorithm uses optimized typed byte arrays and pre-allocated string buffers. 5,000 UUIDs or MAC addresses typically render in under 40 milliseconds on modern devices.
Are any of these generated IDs transmitted over the internet?
No. All identifiers are generated locally in your browser memory via window.crypto. Zero network requests, zero telemetry, and zero server logging are performed.