All UUID generation runs locally in your browser. No data you enter is ever transmitted to a server. UUIDs are not guaranteed unique in all scenarios — always validate for critical production use.
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Generate v4, v7, v1 & NIL UUIDs — Instantly In Your Browser
Choose your UUID version, set quantity up to 100, apply format options, and export as plain text, JSON, or CSV. Includes a built-in validator to decode and inspect any UUID. All generation runs locally — your data never leaves your device.
All UUID generation runs locally in your browser. No data you enter is ever transmitted to a server. UUIDs are not guaranteed unique in all scenarios — always validate for critical production use.
crypto.randomUUID() and crypto.getRandomValues() — the browser's cryptographically secure random number generator. The count, version, and format are shown above the output panel. Press Enter in the quantity field to generate without the mouse..txt, .json, or .csv file. Use the Validate / Decode panel to paste any UUID and instantly see its version, RFC variant, and what that version is used for.A UUID (Universally Unique Identifier) is a 128-bit number represented as 32 hexadecimal digits in five hyphen-separated groups — for example, 550e8400-e29b-41d4-a716-446655440000. UUIDs are used in databases, APIs, and distributed systems where a unique identifier is required without a central authority to issue sequential IDs. The term GUID (Globally Unique Identifier) is synonymous and common in Microsoft ecosystems.
Version 4 UUIDs are randomly generated and the most widely used general-purpose choice. Version 1 encodes a 60-bit timestamp and the MAC address (or random node ID in a browser), making them time-sortable but potentially exposing system information. Version 7 (RFC 9562, 2024) encodes a Unix millisecond timestamp in the top 48 bits and random data in the rest, combining time-ordering with strong randomness. The NIL UUID is all zeros and serves as a null placeholder.
Yes. Version 4 UUIDs use crypto.randomUUID(), the browser's built-in CSPRNG. The random portions of v1 and v7 also use crypto.getRandomValues(). However, UUIDs are identifiers, not secrets — do not use them as passwords, API keys, or cryptographic tokens.
Version 7 was standardized in RFC 9562 (April 2024). It encodes a Unix timestamp in milliseconds in the most significant 48 bits, making UUIDs naturally time-sortable. When used as database primary keys, this means new rows always append near the end of the B-tree index, eliminating the page splits and fragmentation caused by random v4 UUIDs. RFC 9562 explicitly recommends v7 over v1 and v6 for new applications.
The NIL UUID (00000000-0000-0000-0000-000000000000) has all 128 bits set to zero. It is used as a null or placeholder identifier in contexts where a UUID field is required but no specific ID is intended — for example, an unset foreign key, a default struct value, or a sentinel in an API protocol.
Yes, and Version 7 is the best choice for this. Its time-ordered structure means new records cluster at the end of the index tree, preserving page locality and reducing fragmentation. Random v4 UUIDs scatter inserts across the index, causing significant page splits over time. PostgreSQL, MySQL, SQL Server, and most modern databases support a native UUID type.
Disclaimer: QuickITTools.com and EnterPlanet LLC strive to make our tools as accurate as possible. This tool is provided for informational and educational purposes only. All UUID generation is performed locally in your browser — no data is transmitted to our servers. UUIDs are provided as-is without guarantee of uniqueness or suitability for any particular purpose.