UUID / GUID Generator
Generate UUID v4 identifiers in your browser, then copy or download them.
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Choose a format and quantity, then generate.
About UUID / GUID
What are UUIDs and GUIDs?
A UUID (Universally Unique Identifier) is a 128-bit identifier. GUID is a name commonly used in the Microsoft ecosystem, usually referring to the same kind of identifier. The standard text representation has 32 hexadecimal characters grouped as 8-4-4-4-12, separated by hyphens.
How is UUID v4 generated?
Version 4 uses random data. Six bits identify the version and variant; the remaining 122 bits are random. Collisions are very unlikely, but uniqueness is not absolute. Use a unique constraint when your data requires it. The current UUID specification is RFC 9562, which supersedes RFC 4122.
What do the output formats change?
Uppercase letters, omitted hyphens, and surrounding braces change only the text representation, not the UUID value. Changing the format updates the displayed results, clipboard text, and download without generating new identifiers. Use the format expected by the receiving system.
How does this tool handle data?
Generation, copying, and TXT file creation happen in your browser; generated results are not uploaded. The tool uses crypto.randomUUID(), or crypto.getRandomValues() with the version and variant bits set when randomUUID() is unavailable. Each generation replaces the current results. TXT files contain one UUID per line, without a header or row numbers.
References: RFC 9562 §5.4 · Web Crypto: randomUUID()