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UUID Generator

Generated with the browser's secure random generator. Nothing is sent to a server.

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Fully random 122-bit identifier. The most widely used UUID version.

0 IDs

    UUID / ULID Inspector

    What is a UUID?

    A UUID (Universally Unique Identifier), also called GUID, is a 128-bit value used to identify records without a central authority. Version 4 is purely random, while version 7 embeds a timestamp so new IDs sort naturally, which keeps database indexes efficient.

    Features

    • • Generate up to 1,000 UUID v4, UUID v7, ULID or NanoID values at once
    • • Uppercase and hyphen-free output options
    • • Copy all results or download them as a .txt file
    • • Inspect any UUID or ULID to see its version, variant and embedded timestamp

    Secure & Private

    IDs are created with crypto.getRandomValues directly in your browser. No data is transmitted or stored on our servers.

    100% client-side generation.

    How to use the UUID Generator

    1. 1

      Choose the ID type: UUID v4 (random), UUID v7 (time ordered), ULID, NanoID or the Nil UUID.

    2. 2

      Set how many IDs you need, and for NanoID the length. Toggle uppercase or hyphens if your system expects a specific format.

    3. 3

      Press Generate, then copy all IDs or download them as a text file for a migration script or spreadsheet.

    4. 4

      Paste any UUID or ULID into the inspector to see its version, variant and, for v1, v7 and ULID, the timestamp encoded inside it.

    Practical examples

    Database primary keys

    UUID v7 starts with a millisecond timestamp, so new rows are inserted at the end of a B-tree index. In PostgreSQL or MySQL this avoids the index fragmentation that random v4 keys cause.

    Idempotency keys

    Payment APIs such as Stripe accept an Idempotency-Key header. A fresh v4 UUID per request makes a retry safe without charging twice.

    Short public IDs

    NanoID produces short, URL-friendly IDs like V1StGXR8_Z5jdHi6B-myT, useful for share links and invite codes where a 36-character UUID looks too long.

    Debugging existing IDs

    Paste an ID from a log to check whether it is v4 or v7 and, for v7 or ULID, when the record was created.

    Frequently asked questions

    Can two UUID v4 values collide?+

    In practice no. A v4 UUID has 122 random bits; you would need to generate about 2.7 quintillion of them before the chance of a single duplicate reaches 50%.

    UUID v4 or v7?+

    Use v7 for database keys and anything you want to sort by creation time. Use v4 when the ID must not reveal when it was created, for example in public URLs.

    What is the difference between UUID and ULID?+

    Both are 128-bit. ULID is written as 26 Crockford Base32 characters and sorts by time as text. UUID v7 offers the same ordering in the standard 36-character UUID format that databases support natively.

    Are the IDs generated securely?+

    Yes. Random bits come from crypto.getRandomValues in your browser, and nothing is sent to a server.

    From the blog