ULID & NanoID generator
Unique time-sortable identifiers, an alternative to UUID.
- Instant
- Free
- Private (processed locally)
- No sign-up
Unique identifiers, but better than UUID
UUID v4 is random and unreadable, and breaks indexes when used as a key. This tool generates two modern alternatives: the ULID (sortable by creation time) and the NanoID (short and URL-safe), with cryptographic randomness.
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Choose the type
ULID (sortable) or NanoID (compact, adjustable size).
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Set the quantity
From 1 to 100 identifiers at once.
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Copy
The whole batch goes to your clipboard.
ULID, NanoID or UUID?
| Format | Length | Main strength |
|---|---|---|
| ULID | 26 characters | Sortable by creation time |
| NanoID | 21 characters (adjustable) | Short and URL-safe |
| UUID v4 | 36 characters | Universal standard, but not sortable |
Randomness from crypto.getRandomValues, all local. The ULID is ideal as a database primary key; the NanoID, as a short identifier in a public URL.
Frequently asked questions
What is a ULID and how does it differ from a UUID?
A ULID encodes the creation timestamp in its first 10 characters, followed by 16 random ones. As a result, two ULIDs generated at different moments sort naturally in chronological order, which a (fully random) UUID v4 does not allow.
Why is time sorting useful?
In a database, sortable keys avoid index fragmentation: new rows insert at the end rather than at random. You can also paginate or sort by date without a dedicated “created_at” column, just with the primary key.
What is a NanoID?
It is a compact random identifier (21 characters by default, versus 36 for a UUID) using a URL-safe alphabet. Shorter, it stays statistically just as safe against collisions for reasonable volumes, and fits better in a URL.
Is the generation really secure?
Yes: the randomness comes from crypto.getRandomValues, the browser’s cryptographic generator, not Math.random (predictable). Everything is generated locally, no identifier passes through a server.