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Developer Tools · Updated October 19, 2026

UUID Generator (v4)

You can generate 1 to 100 random version 4 UUIDs in your browser, choose uppercase or hyphen-free output, then copy them all or download a text file.

Runs in your browserFree · No sign-up · No watermark
SettingsUUIDRuns in your browser
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Everything runs locally in this tab. No file is uploaded while the tool loads.

This tool runs in your tab. Nothing is uploaded and no copy is stored.

How files are handled

At a glance

Formats
Settings → UUID
Processing
In your browser
Max size
Device memory bound
Price
Free, no account
Updated
October 19, 2026
All Developer Tools

About UUID Generator

UUID version 4 is a 128-bit identifier with 122 random bits, written as five groups of hexadecimal characters. It is the default choice for database rows, API resources, idempotency keys and request IDs because it needs no central authority and can safely be generated on the client.

This generator asks the browser for cryptographic randomness, uses crypto.randomUUID when it exists and falls back to crypto.getRandomValues on older engines. You can produce up to a hundred at once, switch case, drop the hyphens for compact storage and download the list as a text file.

What this tool does

The details that matter when you use UUID Generator for real work.

  • Cryptographic randomness

    Values come from crypto.randomUUID or crypto.getRandomValues rather than Math.random, so they are suitable for identifiers and request keys.

  • One to one hundred at a time

    Generate a single UUID for a test or a batch of a hundred for seeding a dataset or a fixture file.

  • Uppercase and hyphen options

    Match APIs that expect uppercase output, or remove the hyphens when a database stores UUIDs as 32 hexadecimal characters.

  • Copy all or download

    Copy the whole list to the clipboard in one click, or download a plain text file with one UUID per line.

  • No account and no tracking

    Generation happens entirely in the page; no UUID is sent to a server and no history is kept.

How to use UUID Generator

No account, no installation — the whole job happens in this browser tab.
  1. 01

    Set how many UUIDs you need

    Drag the count slider between 1 and 100; the list regenerates automatically when the count changes.

  2. 02

    Choose formatting

    Enable uppercase if a system expects it, and turn off hyphens when you need the compact 32-character form.

  3. 03

    Regenerate if needed

    Press Regenerate for a fresh batch without changing the settings.

  4. 04

    Copy or download the list

    Use Copy all for the clipboard, or Download .txt for a file with one UUID per line.

Supported formats and limits

Input
Settings
Output
UUID
Processing
Client-side, in your browser. Nothing is uploaded.
Maximum size
Bound by the memory available to your browser tab.
Requirements
Chrome, Edge, Firefox or Safari · Secure context for the Web Crypto API

Limitations worth knowing

  • The generator produces random identifiers, not ULIDs or time-sortable UUIDs; use a dedicated library when ordering matters.
  • Output is a plain text list only, with no CSV or JSON formatting options.
  • A browser without a secure random source cannot generate UUIDs here, and the tool deliberately refuses to fall back to an insecure algorithm.

Privacy and file handling

UUIDs are generated inside this browser tab with the Web Crypto API. Nothing is uploaded, stored or logged, and the page keeps no history of previously generated identifiers.

Read the full privacy policy

UUID Generator FAQ

Short, direct answers to the questions people ask before using this tool.
What makes a UUID version 4 different from other versions?
Version 4 is generated from random data, with six of its 128 bits reserved to mark the version and variant. That leaves 122 random bits, so the value carries no timestamp, machine address or sequence information.
Are the UUIDs generated here sent to a server?
No. The values are created by the browser's cryptographic random generator inside this page and never leave your device, so the tool is safe for identifiers that will appear in internal systems.
Can two version 4 UUIDs ever collide?
In theory yes, but the probability is negligible in practice: you would need to generate billions of values before a collision became plausible. The birthday bound for 122 random bits is around 2^61 values.
Why would I remove the hyphens from a UUID?
Some databases and APIs store UUIDs as 32 hexadecimal characters without separators, which saves four bytes and matches columns typed as binary. Keep the hyphens for interchange and human reading unless the destination requires otherwise.
What is the difference between UUID v1 and v4?
Version 1 combines a timestamp with a node identifier, often a MAC address, which makes values sortable but can leak when and where they were created. Version 4 is random, so it reveals nothing about the machine or the time.
Can I use these UUIDs as database primary keys?
Yes, version 4 UUIDs are widely used as primary keys. Random values can fragment B-tree indexes more than sequential keys, so high-write tables sometimes prefer a sequential or time-ordered identifier instead.
What happens in a browser without crypto.randomUUID?
The generator falls back to crypto.getRandomValues, fills 16 bytes and sets the version and variant bits itself. Older browsers without any secure random source show an error rather than falling back to an insecure generator.

Background reading

Format guides that explain the trade-offs behind UUID Generator.