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UUID Generator

Generate UUID v4 and v7 values in bulk, with or without hyphens.

    Processed on your device. Nothing you type is sent anywhere.

    How to use: UUID Generator

    1. Choose a version: v4 (random) or v7 (time-sortable).
    2. Enter a quantity (up to 1,000 at a time) and select hyphens or uppercase if your system requires them.
    3. Click Generate, then Copy all — one UUID per line.

    About this tool

    UUID anatomy

    A UUID has 128 bits, written as 32 hexadecimal digits, usually in five groups of 8-4-4-4-12 (36 characters with hyphens):

    0192d4e6-7a3b-7c41-9f2e-5b8d0c6a1e73

    • The 13th digit indicates the version — here, 7. In a UUID v4, it's always 4.
    • The 17th digit indicates the variant and, in UUIDs that follow the current standard, is 8, 9, a, or b.

    The versions are defined in RFC 9562 (IETF, 2024), which replaced the earlier RFC 4122 and officially introduced version 7.

    v4 or v7: which should you choose?

    FeatureUUID v4UUID v7
    Contents122 random bitsdate and time in milliseconds (48 bits) + random bits
    Orderingnonelater UUIDs sort "higher"
    Typical usestokens, public identifiers, file namesdatabase primary keys, logs, events
    Reveals anything?noreveals the approximate creation time

    In databases with B-tree indexes (PostgreSQL, MySQL/InnoDB, SQL Server), v4 keys are inserted at random positions in the index, while v7 keys are almost always added at the end. This reduces fragmentation in large tables.

    Frequently asked questions

    Are UUIDs and GUIDs the same thing?

    In practice, yes. GUID is the name Microsoft uses (in .NET, SQL Server, and Windows) for the same 128-bit identifier. Some Microsoft systems display GUIDs in uppercase and surrounded by braces, but the value is the same.

    Can two UUIDs be identical?

    In theory, yes. In practice, no: a UUID v4 has 122 random bits, so the chance of a collision only becomes significant after billions upon billions of identifiers. These UUIDs come from your browser's cryptographic random number generator (crypto.getRandomValues).

    Can I use a UUID as a password or secret token?

    For session tokens or passwords, use a password generator or longer random values instead. A UUID v7 isn't entirely random: part of it is the date and time it was created.

    Is it really free? Is there a daily limit?

    It's free with no daily limits. Processing happens on your device, so there's no per-use cost and no need to limit you.

    Does it work on phones?

    Yes. The site works in any modern browser on Android, iPhone, Windows, Mac, and Linux—no installation needed.

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