Generate K-Sortable Unique Identifiers (KSUIDs) for use in distributed systems, databases, and applications requiring unique, time-sortable keys. KSUIDs combine a timestamp with random data to create collision-resistant, sortable identifiers.
A KSUID generator creates K-Sortable Unique Identifiers that combine time-based sorting with cryptographic uniqueness. Unlike traditional UUIDs, KSUIDs are chronologically sortable and perfect for distributed systems requiring unique identifier generation without coordination between servers.
Key benefits of using a KSUID generator:
A KSUID (K-Sortable Unique Identifier) is a 20-byte sortable identifier that consists of:
When represented as a string, a KSUID is encoded in base62 and is exactly 27 characters long.
The KSUID structure consists of three key components:
Timestamp Component (4 bytes): Represents seconds since the KSUID epoch (2014-05-13T16:53:20Z), enabling chronological sorting of generated IDs.
Random Component (16 bytes): A cryptographically secure random number ensuring uniqueness even when multiple KSUIDs are generated simultaneously.
Base62 Encoding: The combined 20 bytes are encoded using base62 (A-Z, a-z, 0-9) to produce the final 27-character URL-safe string.
A KSUID can be represented mathematically as:
Where:
The timestamp is calculated as:
T = \text{floor}(\text{current_time} - \text{KSUID_epoch})
Where KSUID_epoch is 1400000000 (2014-05-13T16:53:20Z).
KSUIDs are ideal for modern applications requiring sortable unique identifiers. Here are the most common use cases:
Generate unique IDs across multiple servers without coordination or central authority. Perfect for microservices architectures.
Use KSUIDs as primary keys in databases where chronological ordering matters, eliminating the need for separate timestamp columns.
Create short, unique, URL-safe identifiers for web applications, APIs, and public resources without special encoding.
Correlate log entries across different services in distributed systems while maintaining chronological order.
Track events chronologically with built-in timestamps for compliance and debugging purposes.
KSUIDs provide significant advantages over traditional identifier systems:
Unlike UUIDs, KSUIDs can be sorted chronologically, making them ideal for database indexing and log analysis.
Generate unique identifiers independently across multiple servers without risking collisions or requiring central coordination.
More compact than UUIDs when represented as strings, saving storage space and improving readability.
Built-in timestamp enables time-based sorting and filtering without separate timestamp fields.
Base62 encoding makes KSUIDs safe for URLs without additional encoding requirements.
The 16-byte random component makes collisions virtually impossible, even at high generation rates.
Follow these simple steps to generate KSUIDs online:
Pro Tip: Generate KSUIDs in batches when setting up new systems or migrating existing data.
Learn how to generate KSUIDs programmatically in your preferred programming language:
1## Python
2import ksuid
3
4new_id = ksuid.ksuid()
5print(f"Generated KSUID: {new_id}")
61// JavaScript
2const { ksuid } = require('ksuid')
3
4const newId = ksuid()
5console.log(`Generated KSUID: ${newId}`)
61// Java
2import com.github.ksuid.KsuidGenerator;
3
4public class KsuidExample {
5 public static void main(String[] args) {
6 String newId = KsuidGenerator.generate();
7 System.out.println("Generated KSUID: " + newId);
8 }
9}
101// C++
2#include <iostream>
3#include <ksuid/ksuid.hpp>
4
5int main() {
6 ksuid::Ksuid newId = ksuid::Ksuid::generate();
7 std::cout << "Generated KSUID: " << newId.string() << std::endl;
8 return 0;
9}
101## Ruby
2require 'ksuid'
3
4new_id = KSUID.new
5puts "Generated KSUID: #{new_id}"
61// PHP
2<?php
3require_once 'vendor/autoload.php';
4
5use Tuupola\KsuidFactory;
6
7$factory = new KsuidFactory();
8$newId = $factory->create();
9echo "Generated KSUID: " . $newId . "\n";
10?>
111// Go
2package main
3
4import (
5 "fmt"
6 "github.com/segmentio/ksuid"
7)
8
9func main() {
10 newId := ksuid.New()
11 fmt.Printf("Generated KSUID: %s\n", newId.String())
12}
131// Swift
2import KSUID
3
4let newId = KSUID()
5print("Generated KSUID: \(newId)")
6KSUIDs are chronologically sortable while UUIDs are not. KSUIDs also have embedded timestamps and are more compact at 27 characters vs UUID's 36 characters.
KSUIDs have extremely low collision probability due to their 16-byte random component. The chance of collision is virtually zero even with billions of IDs generated.
Yes, KSUIDs are excellent for database primary keys, especially in distributed systems where auto-incrementing integers aren't suitable.
The KSUID epoch starts at 2014-05-13T16:53:20Z (timestamp 1400000000), different from the Unix epoch.
Yes, KSUIDs use base62 encoding (A-Z, a-z, 0-9) making them completely URL-safe without additional encoding.
KSUIDs can be generated very quickly since they don't require coordination between systems or database lookups.
Yes, you can extract the embedded timestamp from any KSUID to determine when it was generated.
KSUIDs are supported in most popular programming languages including Python, JavaScript, Java, Go, PHP, Ruby, and more.
Ready to implement sortable unique identifiers in your application? Use our free KSUID generator tool to create time-ordered, globally unique identifiers for your distributed systems, databases, and applications.
Generate your first KSUID now and experience the benefits of chronologically sortable unique identifiers!
Discover more tools that might be useful for your workflow