UUID Generator
Generate UUIDs (v1, v4, v5), ULIDs, and NanoIDs entirely in your browser. Bulk generate up to 1,000 IDs and download them as a text file. Nothing leaves your device.
UUID v4 — Random, cryptographically secure
UUID v1 — Timestamp-based, monotonically increasing
UUID v5 — Deterministic, namespace + name (SHA-1)
ULID — Universally Unique Lexicographically Sortable Identifier
NanoID — Compact, URL-safe random ID
Bulk Generate
Generate multiple IDs at once in the currently selected format.
UUID formats explained
UUID v4 is the safest default. It is generated entirely from random bits using crypto.randomUUID() — no timestamp, no node information. Use v4 for session tokens, database primary keys, and correlation IDs.
UUID v1 embeds a timestamp, making it sortable by creation time. Useful for event logs and time-series records where ordering matters. In browsers, the node component is randomised (no real MAC address is used).
UUID v5 is deterministic: given a namespace and a name string, it always returns the same UUID. Ideal for turning a well-known name (like a domain or email address) into a stable, reproducible identifier.
ULID is a 26-character Base32 string that sorts lexicographically by creation time. This makes it an excellent replacement for UUID v4 in database primary keys — it avoids index fragmentation while remaining globally unique.
NanoIDis a compact, URL-safe alternative to UUID. At 21 characters it matches UUID v4's collision resistance, but is easier to embed in URLs and shorter to type.