ULID Generator
Generate ULIDs in bulk — 128-bit IDs that sort by creation time thanks to a millisecond timestamp prefix, then 80 bits of secure randomness, in 26 URL-safe Crockford Base32 characters. Everything runs in your browser; nothing is uploaded.
- 🔒 100% private — no uploads
- 🆓 Free, no watermark
- 📱 Works on any device
How to generate a ULID
- 1
Choose how many
Set how many ULIDs you want with the slider — generate one or a whole batch at once.
- 2
Generate instantly
Each ULID is a millisecond timestamp plus 80 bits from your browser’s cryptographic random generator — nothing is requested from a server.
- 3
Copy the batch
Copy them all with one click, and hit regenerate for a fresh set anytime.
Why use ULID Generator?
Sortable by time
A 48-bit millisecond timestamp sits at the front, so ULIDs sort in creation order — great as database keys, like UUID v7.
URL-safe Base32
26 Crockford Base32 characters: compact, case-insensitive and free of the ambiguous I, L, O and U.
100% private
Everything runs locally in your browser with JavaScript. Your input is never uploaded, stored or seen by anyone — it even works offline once the page has loaded.
Works on any device
No install and no account. Runs in any modern browser on Windows, macOS, Linux, Android or iPhone.
Why time-sortable IDs matter
Purely random IDs (like UUID v4) scatter database inserts across the whole index, so every write touches a random page — bad for cache hits and B-tree locality on busy tables. A ULID’s first 48 bits are a millisecond timestamp, so consecutive inserts land next to each other and rows sort by creation time with a plain ORDER BY on the key. You get the uniqueness of 80 random bits without giving up insert locality.
Compact and copy-paste friendly
A ULID is 26 characters of Crockford Base32 — no hyphens, case-insensitive, and the ambiguous letters I, L, O and U are excluded so a read-aloud or hand-typed ID survives. That makes ULIDs pleasant in URLs, filenames and logs where a 36-character hyphenated UUID is clumsy. If your ecosystem expects UUIDs, v7 gives similar time-ordering in UUID form — both are generated on this site.
Frequently asked questions
What is a ULID?
A ULID is a 128-bit unique identifier that is lexicographically sortable. The first 48 bits are a millisecond timestamp and the remaining 80 bits are random, encoded as 26 Crockford Base32 characters — so it sorts in creation order while staying unguessable.
ULID or UUID — which should I use?
Both are unique. ULIDs sort by creation time (like UUID v7) and are shorter and URL-safe (26 vs 36 characters), which is handy for keys and URLs. UUIDs are more universally supported across languages and databases. If you want time-ordering and compact IDs, ULID is a great fit.
Is my data uploaded to a server?
No. The tool runs entirely in your browser, so whatever you paste stays on your device. It’s safe for tokens, secrets and confidential data, and works offline once loaded.