Free Tools → UUID & ULID Generator

UUID & ULID Generator

Generate unique identifiers instantly in your browser. Supports UUID v4, UUID v7, and ULID. No data sent to any server.

⚙️ Generator Settings

ID Format

UUID v4 (Random) UUID v7 (Time-sortable) ULID (Crockford's Base32)

How Many?

(1–100)

Output Format

Plain text (one per line) JSON array CSV

📋 Generated IDs

Click "Generate" above to create unique identifiers.

ℹ️ About Each Format

UUID v4 — 128-bit random identifier. Format: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx. Most widely used UUID type. Great for database primary keys, session tokens, and distributed systems. 122 bits of randomness = near-zero collision probability.

UUID v7 — Time-ordered UUID (RFC 9562). Combines a Unix timestamp (milliseconds) with random bytes. First 48 bits encode time, making IDs naturally sortable. Perfect for databases where insertion order matters (think auto-increment replacement).

ULID — Universally Unique Lexicographically Sortable Identifier. 26 characters using Crockford's Base32. First 10 chars = timestamp, last 16 chars = randomness. Sortable, URL-safe, and compact. Popular in microservices and event-driven architectures.

Free UUID Generator — No Signup, No Server

This UUID generator runs entirely in your browser using the Web Crypto API for cryptographically secure randomness. No identifiers are sent to any server, logged, or stored. Generate with confidence.

UUID v4 vs UUID v7 vs ULID

UUID v4 is the classic random UUID — use it when you need pure randomness and don't care about sort order. UUID v7 is the modern replacement that embeds a timestamp, making it sortable and better for database indexes. ULID uses Crockford's Base32 encoding for a compact, lexicographically sortable string that's popular in microservices.

How secure are these identifiers?

All random bytes are generated using crypto.getRandomValues(), which provides cryptographically strong random numbers. UUID v4 has 122 bits of randomness (6 bits are fixed by the version/variant fields), giving a collision probability so low it's effectively zero for any practical use case.