UUID Generator

Name: UUID Generator
Author: EverydayTools

Generate UUID v4, v7 (time-sortable), or v1—validate, highlight version bits, export bulk JSON/CSV, and share settings. All client-side.

Runs in your browsercrypto.randomUUID()· v1 / v4 / v7 · never uploaded

UUID validator

Paste with or without hyphens—version nibble highlighted on results.

Version

Cryptographically random—best default for DB keys and APIs.

Live generateDedupe batch

Quantity

Generated UUIDs

Ready to generate

No UUIDs yet

v7 is ideal for new DB schemas needing sortable IDs.

Code snippets

Browser

crypto.randomUUID();

Node.js

import { randomUUID } from "crypto";
randomUUID();

Python

import uuid
str(uuid.uuid4())

PostgreSQL

gen_random_uuid()  -- v4

By Muhammad Abdullah Rauf · Founder, EverydayTools.proUpdated 2026

What is a UUID generator?

A UUID generator creates RFC 4122/RFC 9562 identifiers (v1, v4, or v7) in your browser using Web Crypto—no server upload.

A UUID (Universally Unique Identifier) is a 128-bit value shown as 32 hexadecimal digits in five groups (8-4-4-4-12). RFC 4122 defines v1 (timestamp-based) and v4 (random); RFC 9562 adds v7 for time-ordered random IDs that improve database index locality compared to random v4.

Developers use UUIDs as database primary keys, correlation IDs in logs, file names, and distributed-system entity IDs. GUID is Microsoft's name for the same concept—most modern GUIDs are RFC-compatible.

This tool generates v1, v4, or v7 UUIDs in bulk (up to 1,000 per run), formats them lowercase/uppercase/without hyphens, validates pasted UUIDs (with or without hyphens), highlights version and variant nibbles, keeps a local history, and exports plain text, JSON, or CSV—all in your browser without sending values to a server.

Generate v4, v7, or v1 UUIDs locally—bulk copy, validate, export; never uploaded.

Quick answers

Concise answers for common searches — definitions, steps, and comparisons.

Are generated UUIDs uploaded to a server?

No. Generation and validation run entirely in your browser with the Web Crypto API. UUIDs are never transmitted to EverydayTools during normal use.

UUID v4 vs v1—which should I use?

Use v4 for general-purpose unique IDs (privacy-friendly, no MAC/timestamp leakage). Use v1 when you need time-correlated ordering; note v1 can expose creation time and node hints.

What is the difference between UUID and GUID?

GUID is Microsoft's term; in practice GUIDs are UUIDs following RFC 4122. .NET Guid.NewGuid() produces v4-style random UUIDs compatible with other systems.

How browser UUID generation works

v4 calls crypto.randomUUID() when available, else fills random bytes and sets version 4 and RFC 4122 variant bits. v1 composes timestamp, clock sequence, and random node per RFC 4122 layout.

Formula

UUID = 128 bits → 8-4-4-4-12 hex groups with version (M) and variant (N) nibbles

Limitations

v4 UUIDs are identifiers—not password substitutes or long-term secrets alone
v5 deterministic UUIDs are not generated in this tool (use hash-based workflows elsewhere)
Math.random fallback is weaker than crypto—modern browsers use Web Crypto

How to use UUID Generator

Choose UUID version
Select v4 (random) for most keys, v7 for new time-sortable schemas, or v1 when you need legacy timestamp ordering.
Set count and format
Pick how many UUIDs to generate (presets 10/50/100 or up to 1,000) and output format: lowercase, uppercase, or no hyphens.
Generate and review
Click Generate—or enable auto-generate when options change. Each row shows the formatted UUID ready to copy.
Validate existing UUIDs
Paste any UUID into the validator to confirm RFC 4122 format, version (v1/v4), and variant before using it in production data.
Export for your stack
Copy all as newline, JSON array, or CSV; download a .txt file, or copy browser/Node.js snippets for programmatic generation.

UUID Generator examples

Single v4 for a Postgres primary key

Input

Version v4 · count 1

Output

e.g. f47ac10b-58cc-4372-a567-0e02b2c3d479

Copy into migrations, seed scripts, or ORM defaults.

Bulk v4 for test fixtures

Input

Count 100 · JSON export

Output

["uuid-1", "uuid-2", …]

Paste into Jest/Playwright fixtures or mock API responses.

Validate a log correlation ID

Input

Paste UUID from log line

Output

Valid · v4 · RFC 4122 variant

Confirm the ID is well-formed before tracing across services.

Who uses UUID Generator?

Common real-world scenarios where this tool saves time.

Database primary keys

Generate v4 UUIDs client-side before insert to avoid coordination across microservices and shards.

API resource identifiers

Assign opaque IDs to REST resources, webhooks, and message queue events without sequential leaks.

Test data and mocks

Bulk-generate hundreds of unique IDs for unit tests, load tests, and demo environments.

Debugging and validation

Paste UUIDs from logs or configs to verify version, variant, and string format before deployment.

Workflow guides

Step-by-step chains that connect related tools for common tasks.

Seed a development database

Select v4 and generate the row count you need.
Copy as CSV or JSON for import scripts.
Validate any legacy UUIDs pasted from dumps using the validator.

Reference tables

UUID structure (RFC 4122)

Part	Position	Meaning
xxxxxxxx	1–8 (32 bits)	Random (v4) or timestamp low (v1)
xxxx	10–13 (16 bits)	Random (v4) or timestamp mid (v1)
Mxxx	15–18	Version digit—4 for v4, 1 for v1
Nxxx	20–23	Variant—8/9/a/b for RFC 4122
xxxxxxxxxxxx	25–36 (48 bits)	Random (v4) or node id (v1)

UUID v1 vs v4 vs v5

Version	How it is built	This tool
v1	Timestamp + clock + node	Generate + validate
v4	Random bytes	Generate + validate (privacy default)
v7	Unix ms + random (RFC 9562)	Generate + validate (DB-friendly)
v5	SHA-1 of namespace + name	Not generated here

UUID vs auto-increment primary keys

Approach	Pros	Cons
UUID v4	Global uniqueness, opaque URLs, client-side generation	16 bytes, random inserts fragment some indexes
Auto-increment	Small, fast indexes, human-readable sequence	Leaks row counts, hard to merge shards
UUID v7	Time-sorted + random (this tool)	Default for new index-friendly schemas

When to use UUID Generator vs related tools

Related tool	Use this tool when	Use related tool when
Random String Generator	You need standard RFC 4122 UUID strings for databases and APIs.	You need custom alphabet/length tokens rather than UUID layout.
API Key Generator	You want opaque unique identifiers with UUID structure.	You need prefixed API keys with entropy suited for auth headers.

Frequently Asked Questions

What is a UUID?

A UUID is a 128-bit identifier formatted as 32 hex digits in five groups. It is designed to be unique across space and time without a central allocator.

Is UUID v4 cryptographically random?

This tool uses crypto.randomUUID() or crypto.getRandomValues()—suitable for unique identifiers. Do not use UUIDs alone as password secrets.

What's the difference between UUID v4 and v1?

v4 is random and privacy-friendly. v1 includes a timestamp and can be roughly time-ordered but may expose creation timing and node information.

What is the difference between GUID and UUID?

GUID is Microsoft's name for UUID. Modern GUIDs follow RFC 4122 and interoperate with UUID fields in databases and JSON APIs.

Should I use UUID v1 or v4?

Default to v4 for most apps. Choose v1 when you deliberately want time-correlated IDs and understand the privacy trade-offs.

Can UUIDs collide?

Collisions are astronomically unlikely for v4 with proper randomness. UUIDs are designed to be practically unique for real-world systems.

How many UUIDs can I generate at once?

Up to 1,000 per run with presets for 10, 50, and 100. Copy individually or export as newline, JSON, or CSV.

Is my data uploaded to a server?

No. All generation and validation runs locally in JavaScript in your browser. UUIDs never leave your device.

Privacy, accuracy, and trust

Privacy

UUID generation and validation use the Web Crypto API in your browser—identifiers are never uploaded to EverydayTools.

Accuracy

Output matches RFC 4122 layout for v1 and v4; validator checks format, version nibble, and variant bits.

For development and testing—use your platform's crypto APIs in production services when policy requires audited libraries.

Part of Developer Tools

More free tools for the same workflow.

UUID validator

Generated UUIDs

Code snippets

What is a UUID generator?

Quick answers

Are generated UUIDs uploaded to a server?

UUID v4 vs v1—which should I use?

What is the difference between UUID and GUID?

How browser UUID generation works

Limitations

How to use UUID Generator

Choose UUID version

Set count and format

Generate and review

Validate existing UUIDs

Export for your stack

UUID Generator examples

Single v4 for a Postgres primary key

Bulk v4 for test fixtures

Validate a log correlation ID

Who uses UUID Generator?

Database primary keys

API resource identifiers

Test data and mocks

Debugging and validation

Workflow guides

Seed a development database

Reference tables

UUID structure (RFC 4122)

UUID v1 vs v4 vs v5

UUID vs auto-increment primary keys

When to use UUID Generator vs related tools

Frequently Asked Questions

What is a UUID?

Is UUID v4 cryptographically random?

What's the difference between UUID v4 and v1?

What is the difference between GUID and UUID?

Should I use UUID v1 or v4?

Can UUIDs collide?

How many UUIDs can I generate at once?

Is my data uploaded to a server?

Privacy, accuracy, and trust

Privacy

Accuracy

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