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Generators & Hashes

UUID Generator Online

Generate random UUIDs (v4) in bulk and copy them.

Updated

This tool runs in your browser. No account or signup is required.

Common UUID Generator tasks

Developers typically reach for this page when they need to generate UUID v4 online; generate UUID v7 online; create multiple UUIDs at once. The tool is built for quick, practical work rather than a generic demo.

What matters in a uuid generator workflow

When developers compare online tools for this job, the useful capabilities tend to center on v4/v7, bulk generation, formatting, copy/download. This page keeps those practical needs in mind while linking to related tools when a different workflow is a better fit.

What is UUID Generator?

UUID Generator creates random UUIDs using your browser's crypto.randomUUID(), the same kind of ID used for database keys and request IDs.

What problem does it solve?

You need IDs for test data, or you need to know whether an ID from a log or database is well-formed. Doing that by eye does not scale.

How to use UUID Generator

  1. Choose how many UUIDs you need.
  2. Press generate.
  3. Copy the list.

Example

Input

Count: 3

Output

3b241101-e2bb-4255-8caf-4136c566a962
(three random UUIDs, different every time)

What you can do with UUID Generator

  • Generate a UUID online
  • Create random GUIDs
  • Bulk UUID generator

Common use cases

  • Seeding test data with unique IDs
  • Checking an ID copied from logs
  • Working out which UUID version a system produces

Related developer tasks

  • Generate a UUID online
  • Create random GUIDs
  • Bulk UUID generator

What a UUID looks like

A UUID is a 128-bit identifier written as 32 hexadecimal digits in five groups, 8-4-4-4-12, for example 3b241101-e2bb-4255-8caf-4136c566a962. In .NET and some databases it is called a GUID.

This tool generates version 4 UUIDs, which are made of random bits. The version digit 4 appears at the start of the third group, and the first digit of the fourth group is 8, 9, a or b.

How the UUIDs are generated

Each UUID comes from your browser's crypto.randomUUID(), which uses a cryptographically secure random source. You can generate 1, 5, 10, 25, 50 or 100 at a time. Nothing is stored or sent anywhere.

When to use UUIDs, and when to think twice

  • Good for: primary keys created on the client, request and correlation IDs, test fixtures and unique file names.
  • Random UUIDs make poor clustered index keys in some databases, because new rows land at random positions and cause page splits. Time-ordered UUIDs such as version 7 are designed for that case. This tool does not generate them.
  • A UUID is an identifier, not a secret. Do not use one as a password or an authorization token.

Related: UUID Validator, UUID Parser, Hash Generator, Timestamp Converter

UUID Generator FAQ

What is a UUID?

A UUID (or GUID) is a 128-bit identifier written as 32 hex digits in five groups, for example 123e4567-e89b-12d3-a456-426614174000.

Which versions does the validator accept?

It accepts the standard layout with a version digit from 1 to 5 and an RFC 4122 variant.

Is my data sent to a server?

The processing runs in your browser, so what you paste into the tool is not uploaded for processing. As with any tool, avoid pasting live secrets you cannot afford to leak.

Is a UUID the same as a GUID?

They share the same 128-bit format. GUID is the name used in Microsoft environments such as .NET and SQL Server.

Can two generated UUIDs be the same?

It is theoretically possible but so unlikely with 122 random bits that applications treat version 4 UUIDs as unique.

Does it generate version 1 or version 7 UUIDs?

No. It generates version 4 (random) UUIDs only.

Looking for something else? Browse all developer tools.

onlinedevelopertool.com is a collection of 54 free, browser-based utilities for the small jobs that interrupt real work: formatting a JSON response, decoding a token, converting a timestamp, generating a UUID or checking a hash. Each tool has its own page with a short explanation, a worked example and answers to common questions, so you can use it and learn what it does at the same time.

There is no account to create and nothing to install. Tools run in your browser, so the text you paste is processed on your own device. The one exception is the Website Status Checker, which sends a request from your browser to the address you enter.

Three steps: paste your input, click the tool, copy the result, all inside your browser
Popular developer utilities: JWT decoder, UUID generator, Base64 decoder, SHA-256 hash, regex tester and timestamp converter

What you can do here

  • JSON Tools

    Format, validate, beautify and minify JSON, generate C#, TypeScript, Java, Python, Go, PHP and Kotlin models from it, or convert between JSON, YAML and CSV.

  • Encoders & Decoders

    URL, Base64 and HTML encoding and decoding, plus a JWT decoder for reading token claims.

  • Generators & Hashes

    Generate UUIDs and JWTs, validate UUIDs, and create MD5, SHA-256 and SHA-512 hashes.

  • Web Tools

    Timestamps, color codes, query strings and cron expressions - the small things web work keeps throwing at you.

  • Text & Data

    Format XML and YAML, count text, change case, make slugs, test regex, diff two texts and convert number bases.

  • Website Checking

    Check whether a website or URL is reachable from your browser.

Quick developer reference

  • JSON

    Keys and strings must use double quotes, and trailing commas and comments are not allowed. Those are the three most common reasons a payload fails to parse.

    Validate JSON

  • JWT

    A JSON Web Token is three Base64URL parts joined by dots: header, payload and signature. Decoding shows the claims but does not prove the token is genuine; only signature verification does.

    Decode a JWT

  • Base64

    Base64 is an encoding, not encryption. Anyone can reverse it, and it makes data roughly one third larger, so never use it to hide secrets.

    Decode Base64

  • UUID

    A version 4 UUID is made of random bits and written as 8-4-4-4-12 hexadecimal characters. Collisions are astronomically unlikely, which is why they work well as identifiers.

    Generate a UUID

  • Timestamps

    A Unix timestamp counts time since 1 January 1970 UTC. Ten digits usually means seconds and thirteen digits usually means milliseconds.

    Convert a timestamp

  • Hashes

    MD5 is fine for quick checksums but is not safe for security. Prefer SHA-256 or SHA-512, and remember that hashing is one-way and is not encryption.

    Create a SHA-256 hash

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