KSUID Generator — K-Sortable Base62 Unique IDs
Generate KSUID strings online — 27-character Base62, 32-bit UTC timestamp + 128-bit randomness. Time-sortable, human-typeable, no delimiters. Designed by Segment for high-volume event streams. 100% local.
Last updated:
Comments3JxULuiG0PFyLSbRwg3waMof7of3JxUM0VwAXzu9Q24vUiRvaADou23JxULtSzXI0VBHbelJRKeEA2dnT3JxUM12hwqkg35gVdKADCtBfZC93JxULzsnGJMzam1iKJwwPMPywon
Frequently Asked Questions
What is a KSUID?
KSUID (K-Sortable Unique IDentifier) was created by Segment for high-volume event ingestion. Each KSUID is 20 bytes: 4 bytes of Unix seconds since the KSUID epoch (2014-05-13) followed by 16 bytes of randomness, encoded as 27 Base62 characters. Sorting lexicographically also sorts by creation time.
How is KSUID different from ULID?
Both are time-sortable IDs. ULID has millisecond timestamp precision (48 bits) and 80 bits of randomness; KSUID has second precision (32 bits) but 128 bits of randomness. ULID uses Crockford Base32; KSUID uses Base62. For most workloads either is fine — pick based on which ecosystem your libraries already support.
When will KSUIDs run out?
The 32-bit second counter (from 2014-05-13) exhausts on 2150-06-19. Roughly 136 years is normally described as 'plenty of time', though rewriting your ID scheme in 2140 is still a task someone will inherit.
Try Next
UUID v7 Generator
Generate UUID v7 identifiers online (RFC 9562). The first 48 bits encode a Unix millisecond timestamp, so v7 UUIDs sort lexicographically by creation time — dramatically better as a database primary key than v4. Bulk generate up to 1000 and inspect the embedded timestamp for each. 100% local.
Related Tools
QR Code
Generate QR codes online for URLs, text, WiFi credentials, and more. Download as PNG or SVG. Everything runs locally.
UUID Generator
Generate random UUIDs (v4) and time-ordered UUIDs (v7) online. Bulk generate up to 1000 at once and copy with one click.
Lorem Ipsum
Generate placeholder Lorem Ipsum text by words, sentences, or paragraphs for mockups, wireframes, and design drafts. Free, no signup, runs entirely in your browser.
Password Generator
Generate strong, random passwords with customizable length and character sets. Free, no signup — cryptographically secure via crypto.getRandomValues, runs entirely in your browser.
NanoID
Generate NanoID strings online — 21 characters, URL-safe alphabet (a-Z, 0-9, -, _), same collision safety as UUID v4 in 40% less space. Bulk generate up to 1000 with custom length. 100% local.
ULID
Generate ULID (Universally Unique Lexicographically Sortable Identifier) strings — 26 characters, 48-bit millisecond timestamp + 80-bit randomness, Crockford Base32. Bulk generate up to 1000. 100% local.