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UUID Generator – Create v4 and v7 UUIDs Online

Create unique identifiers for databases, APIs and test data, one at a time or a thousand at once. Every UUID is generated on your device.

Version

Your UUIDs

How to generate UUIDs

  1. Pick a version: v4 (random) or v7 (time-ordered). A list of UUIDs appears as soon as the page loads.
  2. Enter how many you need, from 1 to 1,000.
  3. Choose the format with the Uppercase, Hyphens and Braces switches.
  4. Copy or download the list as a .txt file, one UUID per line. Press Generate new whenever you want a fresh set.

Features

  • Version 4 UUIDs from the browser's built-in crypto.randomUUID.
  • Version 7 UUIDs following RFC 9562: a 48-bit millisecond timestamp, a counter and random bits, so they sort by creation time.
  • Bulk generation of up to 1,000 UUIDs in one go.
  • Format options: lowercase or uppercase, with or without hyphens, with or without curly braces.
  • Copy all or download as a plain text file, ready to paste into a script, a spreadsheet or a SQL insert.
  • Changing the format keeps the same IDs, so you can compare styles without losing a list.

Why use Fileora's UUID generator

Identifiers often end up as database keys, API tokens or links to private records, so where they come from matters. Some online generators create UUIDs on their server and could, in principle, keep a copy. Fileora creates them in your browser using the same secure randomness that protects encryption keys. The list never leaves your device, and closing the tab discards it.

The tool is free, needs no account and has no daily limit. It works just as well on a phone: generate a batch, tap Copy, and paste the whole list into a message or a note.

Need a secret rather than an identifier? A UUID is unique, but it isn't designed to be a password: use the password generator for that. You can also fingerprint a UUID list or any other text with the hash generator, or paste your IDs into test data and check it with the JSON formatter.

UUID v4 and v7 compared

Both versions share the same 36-character layout of 32 hexadecimal digits in five groups (8-4-4-4-12), and the first digit of the third group always shows the version: 4 or 7. The difference is what fills the rest.

A v4 UUID is almost entirely random. That makes it impossible to guess but also means consecutive IDs are scattered, which forces a database to insert each new row into a random place in its index.

A v7 UUID begins with the current time in milliseconds. IDs created later sort after earlier ones, both as text and as bytes, so new records are appended in order, just like an auto-increment number, while the random part still keeps them unique across servers. IDs created within the same millisecond, such as a large batch generated in one click, share a timestamp, so a 12-bit counter after it keeps them in creation order too.

Frequently asked questions

What is the difference between a UUID and a GUID?

They are the same thing. GUID (globally unique identifier) is the name Microsoft uses, UUID (universally unique identifier) is the name in the standard. Windows tools often show GUIDs in uppercase inside curly braces, which you can reproduce here with the Uppercase and Braces options.

Should I use UUID v4 or v7?

Use v4 when you just need an unpredictable ID and order doesn't matter, such as a file name, a request ID or a public reference. Use v7 for database primary keys: because it starts with a timestamp, new rows land at the end of the index instead of at random places, which keeps inserts fast in PostgreSQL, MySQL and similar databases.

Can two UUIDs ever be the same?

In theory yes, in practice no. A v4 UUID contains 122 random bits. You would need to generate roughly 2.7 quintillion of them before there was an even chance of a single duplicate. A v7 UUID adds 62 random bits to its timestamp and counter, which is still far more than any system needs within one millisecond.

Are the UUIDs generated securely?

Yes. Version 4 IDs come from your browser's crypto.randomUUID function, and version 7 IDs use crypto.getRandomValues for their random part. Both use the operating system's cryptographically secure random number generator, not Math.random. Nothing is fetched from or sent to a server.

Does a v7 UUID reveal when it was created?

Yes. The first 48 bits are the creation time in milliseconds since 1970, so anyone who sees the ID can work out roughly when it was made. If that matters, for example for IDs shown in public URLs, use v4 instead.

Can I remove the hyphens?

Yes. Switch off Hyphens to get the compact 32-character form, which some databases and APIs prefer. The options apply to the whole list at once, so you can switch between formats without generating new IDs.

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