UUID / GUID Generator

Generate cryptographically secure UUID v4 and time-ordered UUID v7 identifiers in bulk. Customize hyphens, uppercase/lowercase, quotes, and JSON array formatting with instant copy.

UUID & GUID Generator

RFC 4122 & RFC 9562

Generate secure Version 4 (random) and Version 7 (time-ordered) UUIDs with custom batch formatting and live inspection.

Generated Output (5 V4)36 chars canonical
#16371bbf9-50b2-445c-867f-1d8b8dd144df
#2ff21870f-7cf8-46d1-9f89-217e6b4d2a4e
#34a279257-a027-48c6-8934-de7f313a5e07
#4ec5c42ca-9521-4122-b0dc-990b11ced18d
#5c514fcbc-7fd1-4a26-87f6-3407692f6211
Save draft on this device

Optional. One draft per tool, stored in this browser only. Saving replaces the previous copy; restoring replaces the current content. Do not use on a shared device. Clearing browser data removes it.

How to use UUID / GUID Generator

  1. 1

    Select your desired UUID version: Version 4 (cryptographically random) or Version 7 (Unix Epoch time-ordered).

  2. 2

    Choose how many UUIDs to generate in bulk (from 1 up to 500 at once).

  3. 3

    Customize formatting options including uppercase/lowercase, canonical hyphens, surrounding quotes, or JSON array layout.

  4. 4

    Click "Generate UUIDs" to produce fresh identifiers, or use the "Validate & Inspect" tab to decode and extract timestamps from existing UUIDs.

  5. 5

    Copy individual UUIDs or click "Copy All" / "Download" to export the generated batch.

Why use this tool?

Modern RFC 9562 UUID v7 Support

Generate high-performance, time-ordered UUID v7 tokens ideal for primary keys in PostgreSQL, MySQL, SQLite, and MongoDB without database B-Tree index fragmentation.

Cryptographically Secure (Web Crypto API)

All random bytes are created directly in your browser using the secure window.crypto engine, ensuring zero predictable sequences or collisions.

Comprehensive Format Customization

Instantly switch between canonical hyphenated, compact 32-character hex, braces format, single/double quotes, or formatted SQL IN and JSON array clauses.

Deep UUID Inspection & Timestamp Decoding

Inspect any pasted UUID to verify RFC 4122 / 9562 compliance, extract the exact embedded timestamp from v1 and v7 UUIDs, and detect version and variant bytes.

Frequently asked questions

What is the difference between UUID v4 and UUID v7?

UUID v4 is entirely pseudo-random (122 random bits), providing maximum entropy. UUID v7 combines a 48-bit millisecond Unix Epoch timestamp with 74 random bits. This allows UUID v7 to be naturally sortable by creation time, drastically improving database index insert speeds and avoiding table fragmentation.

Is a GUID different from a UUID?

GUID (Globally Unique Identifier) is Microsoft’s implementation of the standard UUID (Universally Unique Identifier) defined by RFC 4122. They share the same 128-bit structure and hex format. GUIDs are sometimes rendered with enclosing braces (e.g. {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}).

Can UUIDs collide?

The probability of a collision in UUID v4 is approximately 1 in 2^122 (roughly 1 in 5.3 x 10^36). Generating 1 billion UUIDs per second for 100 years would yield an infinitesimal chance of generating a single duplicate.

Are generated UUIDs sent to or saved on a server?

No. UsefulGo’s UUID Generator operates 100% locally in your browser using the standard Web Crypto API. No generated UUIDs or inspected strings are transmitted over the network or logged anywhere.

Related tools

Developer Tools

URL Slug Generator

Transform titles, headings, and product names into clean, SEO-friendly URL slugs with custom separators, stop word removal, and accent transliteration.

Base64 Encode & Decode

Encode and decode Base64 text and binary data online with UTF-8 character support, URL-safe Base64, and instant clipboard copying 100% in your browser.

JWT Debugger & Decoder

Decode, inspect, and verify JSON Web Tokens (JWT) online. View claims, expiration dates, signature verification, and build tokens safely 100% in your browser.

JSON Formatter & Validator

Format, beautify, validate, and minify JSON data online with instant syntax error highlighting and tree inspection.

Regex Tester & Debugger Online

Test, evaluate, and debug regular expressions in real-time with visual match highlights, capture group inspection, and quick regex cheat sheets.

JSON Tree Viewer

Explore, navigate, and inspect complex JSON payloads with an interactive collapsible tree viewer, type badges, node search, and JSON path copying.