UUID Generator

Generate random UUIDs / GUIDs for your projects

The UUID Generator creates UUIDs in v1, v4, or v7 format directly in your browser, with optional uppercase and no-dashes output. It works well for database keys, fixtures, event IDs, and debugging workflows where you need one ID or a batch quickly. Nothing is generated on a server.

Content reviewed: August 27, 2026

Encrypted with HTTPSProcessed in your browserFree to use

All processing runs locally in your browser. Your files and text are not sent to Tool-web's server.

Actions:

How to Use

Choose the UUID version you want to generate
Set how many IDs you need, from 1 to 100
Optionally switch to uppercase or remove dashes
Click Generate, then copy individual IDs or download the full list

Features

UUID v1, v4, and v7 generation
Generate up to 100 IDs at once
Uppercase and no-dashes output options
Copy each UUID individually or copy the full batch
Download the generated list as a text file

Tips for getting UUID Generator right

Use v4 unless you specifically need time ordering or legacy time-based behavior
Generate several in one batch for seeded test data or fixture records
Keep the hyphenated format — it's what most databases and APIs expect
Remember that uppercase and no-dashes change formatting, not uniqueness
Copy only the count you need; you don't have to take the whole batch

When to choose v1, v4, or v7

Version	Best for	Why
v1	Legacy systems that already expect time-based UUIDs	Includes timestamp structure
v4	General-purpose IDs and test data	Random UUIDs with no ordering built in
v7	Time-ordered inserts and event streams	Keeps a sortable timestamp component

Formatting options that change display, not identity

UPPERCASE changes only the letter casing
No dashes removes separators but does not create a different underlying value
Some APIs require the standard hyphenated format, so keep it unless you know otherwise
Generating in batches is useful for fixtures, imports, and seed data

Real-World Use Cases

Generating IDs for database rows and fixtures
Creating correlation IDs for logs and tracing
Preparing batches of unique values for test imports
Making unique filenames or object keys
Producing sortable event identifiers when v7 fits the system

Best Practices

Use v4 for most ordinary unique-ID needs
Choose v7 when time ordering is genuinely useful
Keep the hyphenated format unless a downstream system requires otherwise
Generate only as many IDs as you need for the current workflow
Store the exact output format your database or API expects to avoid later normalization work

Common Mistakes to Avoid

Assuming every UUID version is purely random
Removing dashes when the receiving system expects the canonical format
Using v1 or v7 without understanding the timestamp component
Generating huge batches when you only need one identifier
Choosing UUIDs when a simple sequential ID would be easier and sufficient

Troubleshooting

If a system rejects the ID, try the standard dashed format first
If you need insertion-friendly ordering, switch from v4 to v7
If you pasted uppercase IDs into a case-sensitive tool, generate lowercase output instead
Use smaller batches if you only need a handful of IDs and the list feels noisy
If compatibility is unclear, default to standard v4 with hyphens

Frequently Asked Questions

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit identifier used to uniquely identify information in computer systems.

Are these UUIDs all random?

Only v4 is purely random. v1 and v7 include time-based structure, which is useful when you want ordering or timestamp behavior.

Can I generate multiple UUIDs at once?

Yes. You can generate up to 100 UUIDs in a single batch.

Privacy & Security

UUID generation happens entirely in your browser using the crypto API. No identifiers are stored or transmitted anywhere.

Tips & Best Practices

Use v4 unless you specifically need time ordering or legacy time-based behavior
Generate several in one batch for seeded test data or fixture records
Keep the hyphenated format — it's what most databases and APIs expect
Remember that uppercase and no-dashes change formatting, not uniqueness

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Tips for getting UUID Generator right

Use v4 unless you specifically need time ordering or legacy time-based behavior

Generate several in one batch for seeded test data or fixture records

Keep the hyphenated format — it's what most databases and APIs expect

Remember that uppercase and no-dashes change formatting, not uniqueness

Copy only the count you need; you don't have to take the whole batch

Version

Best for

Why

Legacy systems that already expect time-based UUIDs

Includes timestamp structure

General-purpose IDs and test data

Random UUIDs with no ordering built in

Time-ordered inserts and event streams

Keeps a sortable timestamp component

Best Practices

Use v4 for most ordinary unique-ID needs

Choose v7 when time ordering is genuinely useful

Keep the hyphenated format unless a downstream system requires otherwise

Generate only as many IDs as you need for the current workflow

Store the exact output format your database or API expects to avoid later normalization work

Common Mistakes to Avoid

Assuming every UUID version is purely random

Removing dashes when the receiving system expects the canonical format

Using v1 or v7 without understanding the timestamp component

Generating huge batches when you only need one identifier

Choosing UUIDs when a simple sequential ID would be easier and sufficient

Troubleshooting

If a system rejects the ID, try the standard dashed format first

If you need insertion-friendly ordering, switch from v4 to v7

If you pasted uppercase IDs into a case-sensitive tool, generate lowercase output instead

Use smaller batches if you only need a handful of IDs and the list feels noisy

If compatibility is unclear, default to standard v4 with hyphens