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UUID Generator
Generate RFC-compliant UUIDs (v1, v4, v5), ULIDs, NanoIDs, and CUIDs instantly in your browser. Generate 1 to 100 at a time, format, copy, or download.
⚙️ Generator
1 UUID
Namespace UUID
Name
Click Generate to create UUIDs…
📖 About UUID Types
UUID v4 Most Common
Randomly generated, 128-bit. Best for most use cases — databases, session IDs, resource identifiers.
UUID v1
Time-based + MAC address. Monotonically increasing. Useful when ordering by creation time matters.
UUID v5 Deterministic
SHA-1 hash of a namespace + name. Same inputs always give the same UUID. Good for reproducible IDs.
ULID
Universally Unique Lexicographically Sortable Identifier. 26-char, URL-safe, sortable by time.
NanoID
Compact, URL-safe random ID. Smaller than UUID, customisable length. Popular in modern web apps.
CUID
Collision-resistant, time-prefixed, readable. Good for distributed systems and client-side ID generation.
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit label used to uniquely identify information in computer systems. This tool generates RFC-compliant UUIDs in v1, v4, v5 formats plus ULID, NanoID, and CUID — all client-side, nothing sent to any server.
Frequently Asked Questions
UUID v1 is based on the current timestamp and MAC address — it is sortable by time but reveals the generating machine. UUID v4 is entirely random — it provides no information about when or where it was created, making it better for security-sensitive use cases.
ULID (Universally Unique Lexicographically Sortable Identifier) is a 26-character ID that is both unique and sortable by creation time. Unlike UUID v4, ULIDs sort chronologically — making them ideal for database primary keys where you want time-based ordering without a separate timestamp column.
UUID v4 has 2^122 possible values. The probability of generating a duplicate in 1 billion UUIDs per second for 100 years is roughly 50% — so for all practical purposes, they are unique. For applications requiring absolute guarantees, use a server-side UUID library.
Yes — these UUIDs follow RFC 4122 standards and are suitable for production use as database primary keys, session tokens, file names, or any identifier requiring uniqueness across systems.
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