PRIVATE BROWSER TOOL

UUID Generator

Generate secure UUID v4 or time-ordered v7 values. Nothing is uploaded.

Options0 characters · 0 lines

Secure identifiers, generated locally.

Choose UUID v4 for random identifiers or UUID v7 for time-ordered database keys.

Result0 characters · 0 lines
Processed locally on this device.
Unicode-safe UTF-8 handling

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Private tools for every writing system.

Your text never leaves this browser. No uploads, accounts, or server processing.

Word segmentation uses your browser’s internationalization engine, with Unicode-safe handling across Latin, CJK, Hangul, Cyrillic, Arabic, Devanagari, and more.

About, editorial standards, and privacy

GENERATOR TOOLS · LOCAL PROCESSING

Generate secure UUID v4 and UUID v7 values locally

The UUID Generator creates one or many standards-shaped identifiers with the browser's cryptographic random source. Choose v4 for random IDs or v7 when time ordering can improve index locality in supported systems.

COMMON USES

When this tool is useful

  • Create IDs for fixtures, prototypes, database rows, or test payloads.
  • Generate a batch of unique values without installing a command-line tool.
  • Compare random UUID v4 and time-ordered UUID v7 formats.

THREE STEPS

How to use the UUID Generator

  1. Choose UUID v4 or UUID v7 and set the number of values.
  2. Select Generate to create the identifiers locally.
  3. Copy the list or download it as a plain-text file.

PRIVACY

Your input stays in this browser

The operation runs on your device and does not require the input to be uploaded. Copy and download actions happen only when you choose them. Avoid treating encoded output as encryption, and follow your own security requirements for confidential data.

WORKED EXAMPLE

UUID Generator: input and expected result

Input or settings

Version: UUID v4
Count: 1
Uppercase: off
No hyphens: off

Expected result

550e8400-e29b-41d4-a716-446655440000

This is an illustrative v4-shaped identifier, not a value to reuse as a unique ID. Generated results change each time.

METHOD & LIMITS

How the UUID Generator works

Processing method

UUID v4 uses crypto.randomUUID when available, otherwise cryptographic random bytes. UUID v7 combines a millisecond timestamp with cryptographic random bytes and the version/variant bits.

What to review

UUID v7 exposes creation time and is not guaranteed to be ordered within the same millisecond. UUIDs are identifiers, not authentication tokens, and no absolute uniqueness guarantee is offered.

References: UUID versions and layouts (RFC 9562)

PRACTICAL NOTES

What to know before using it

Should I use v4 or v7?

Use v4 for widely supported random identifiers; consider v7 when your storage system benefits from time ordering.

Can generated UUIDs be guaranteed unique?

No finite random system offers an absolute guarantee, but properly generated UUIDs have an extremely low collision probability.