UUID Generator
The UUID generator produces universally unique identifiers in four formats: v1 (time-based, encodes a timestamp and MAC address), v4 (random, the most widely used format), v7 (time-ordered random, suitable for use as database primary keys that sort by creation time), and Nanoid (a compact URL-safe random identifier).
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What the UUID generator is for
The UUID generator produces universally unique identifiers in four formats: v1 (time-based, encodes a timestamp and MAC address), v4 (random, the most widely used format), v7 (time-ordered random, suitable for use as database primary keys that sort by creation time), and Nanoid (a compact URL-safe random identifier). Bulk generation, uppercase output, and dash stripping are supported.
Common uses include generating primary keys for database records, creating unique IDs for distributed systems without a central coordinator, generating correlation IDs for request tracing, and producing test data with unique identifiers.
Frequently asked questions
Is UUID v4 guaranteed to be globally unique?
UUID v4 uses 122 random bits. Collision probability is low but not zero and depends on randomness quality and volume. Applications requiring uniqueness still need collision detection; a random identifier is not absolute proof of uniqueness.
What is Nanoid?
Nanoid generates compact, URL-safe random identifiers using a 64-character alphabet (A-Za-z0-9_-). The default 21-character length has collision probability comparable to UUID v4 but in a shorter, more URL-friendly string.
Are the generated UUIDs cryptographically random?
UUID v4 and Nanoid use the browser's crypto.getRandomValues() for cryptographic-quality randomness. UUID v1 is time-based and not random.
Is it safe to use UUIDs as public-facing identifiers?
UUID v4 and Nanoid are suitable as public identifiers because they are random and hard to guess. UUID v1 leaks timing information and a MAC address, so it should not be used in security-sensitive contexts.
References and result limitations
Local results depend on the input and selected options. Retain the input example, format and processing rules when citing a result, and verify the output. Keep keys and other sensitive material out of public examples.
These references explain protocol or format rules; they do not endorse results produced by this site.