HomeTools › UUID Generator (v4)

UUID Generator (v4)

Generate cryptographically random UUID v4 identifiers — single or in bulk — with one-click copy.

🔒 Cryptographically secure (crypto.getRandomValues)

Ctrl + D (or + D on Mac) to bookmark this page instantly

How it works

Pick a version

v4 (random) for tokens, v7 (time-ordered) for database keys, or Nil UUID.

Set count & format

1 to 1000 UUIDs. Choose case, with or without hyphens, or braced.

See instant output

Generated with cryptographically secure random — RFC 9562 compliant.

Copy or download

Copy all to clipboard, or download as CSV for spreadsheets / TXT for scripts.

Generating UUIDs in code

Every modern language has built-in UUID support — here's the correct, cryptographically secure way:



UUID v7 vs UUID v4 — which unique identifier to use

Most people default to UUID v4 because it's the most familiar version, but v7 is the modern choice for database primary keys. This UUID generator supports both plus the special Nil UUID:

🏆 UUID v4 (random)

  • 122 bits of pure randomness
  • Best for security tokens, API keys, session IDs
  • Zero information leakage — safe to expose publicly
  • Collision probability: 1 in 2.71×1018
  • Format: xxxxxxxx-xxxx-4xxx-[89ab]xxx-xxxxxxxxxxxx

🔑 UUID v7 (time-ordered)

  • First 48 bits: Unix timestamp in milliseconds
  • Best for database primary keys — 10-20% faster inserts than v4
  • Sortable by creation time without a separate column
  • Standardized in RFC 9562 (May 2024)
  • Format: xxxxxxxx-xxxx-7xxx-[89ab]xxx-xxxxxxxxxxxx

Cryptographically secure random — why the browser API matters

This UUID generator uses crypto.getRandomValues() and crypto.randomUUID() — the same cryptographic APIs that browsers use for HTTPS keys and password hashing. Many older UUID generators use Math.random(), which is predictable and unsuitable for security-sensitive uses like session tokens or API keys. If someone knows a few of your UUIDs, they can potentially predict the next ones. Cryptographic randomness makes this impossible.

Bulk UUID generation up to 1000 at once, CSV or TXT export

Need a batch for a database migration, test fixtures, or seeding a distributed system? Set the count up to 1000 and download as CSV (with a header row for direct spreadsheet import) or plain TXT (one per line, ready for a script). Every UUID is generated independently — batch generation doesn't reduce randomness.

Generate UUID online — v4, v7 and Nil unique identifier support

This uuid generator (v4) runs entirely in your browser using JavaScript. Provide your input, adjust any settings, and get instant results — nothing is uploaded to a server, making it both fast and completely private.

Whether you need this tool once or use it daily as part of your workflow, it remains completely free with no sign-up, no usage limits, and no interrupting advertisements. Every calculation, conversion and generation happens locally on your device — your data stays yours from start to finish.

Why browser-based tools are better

Server-based tools require uploading your data, waiting for processing, and trusting a third party with your information. This tool eliminates all three concerns: processing happens on your own device, results appear instantly regardless of your internet speed, and the tool continues working even offline once the page has loaded. For professionals handling sensitive data, this local-processing approach is a genuine practical advantage.

Random UUID and GUID use cases

This tool serves content creators, developers, students, designers and everyday users who need a quick, reliable utility without the overhead of installing desktop software or creating yet another online account. It does one job well and gets out of your way — exactly what a good tool should do.

Getting the best results

Start with the highest quality input available, use the specific settings the tool provides rather than accepting defaults, and bookmark the page for instant future access. For sharing with team members, simply share the page URL — no accounts or installations needed on their end.

FeatureDetails
Price100% free, no limits
PrivacyRuns in browser, no uploads
DevicesPhone, tablet, desktop
OfflineWorks after page loads

💡 Key takeaways

  • Free uuid generator (v4) — instant results in your browser
  • No sign-up, no upload, 100% private
  • Works on every device — phone, tablet, desktop
  • No usage limits — free forever
💡

Pro tip: Bookmark this uuid generator (v4) for instant access — it loads in under a second and works offline once cached.

Why choose our tool?

100% Private

Everything runs in your browser. Your data never leaves your device — no uploads, no server processing, no tracking.

Instant Results

No loading screens, no waiting, no queues. Results appear the moment you click — powered by client-side JavaScript.

No Sign-Up Ever

No accounts, no emails, no passwords. Just open the page and start using it — forever free, no strings attached.

Works Everywhere

Phone, tablet, laptop, desktop — any browser, any OS. Fully responsive and works offline once loaded.

Also useful if you searched for: uuid generator, uuid v4 generator, random uuid online, generate uuid, uuid generator bulk, guid generator, uuid maker, unique id generator, uuid v4 online free, random guid generator.

Frequently asked questions

What's the difference between UUID v4 and v7?
v4 is fully random — use it for security tokens, API keys, and anywhere you don't want IDs to leak creation-time information. v7 is time-ordered (first 48 bits are a Unix timestamp) — use it for database primary keys because it produces 10-20% faster inserts than v4 by preserving index locality.
Is this UUID generator cryptographically secure?
Yes — it uses crypto.getRandomValues() and crypto.randomUUID(), the same APIs browsers use for HTTPS keys. Many older UUID tools use Math.random(), which is predictable and unsafe for security uses. This generator is safe for tokens and session IDs.
Can I generate UUIDs in bulk?
Yes — set the count anywhere from 1 to 1000. Download the batch as a CSV file (with header for spreadsheet import) or plain TXT (one UUID per line for scripts). Each UUID is generated independently.
Are UUIDs guaranteed to be unique?
Not guaranteed, but the collision probability for v4 is 1 in 2.71×10¹⁸ — you'd need to generate one billion UUIDs per second for 85 years to reach a 50% collision risk. For any practical purpose they're effectively unique.
What's a Nil UUID and when should I use it?
A Nil UUID is all zeros (00000000-0000-0000-0000-000000000000). It's used as a placeholder or 'none' value in databases and APIs — like NULL, but with a valid UUID format so column types don't need to accept null.
What's the difference between a UUID and a GUID?
No practical difference — GUID (Globally Unique Identifier) is Microsoft's term for the same 128-bit format. Both follow RFC 4122/9562. Some Microsoft docs write GUIDs with braces: {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} — this tool supports that format too.
Can I use these UUIDs commercially?
Yes — UUIDs are just random data, not copyrighted or licensed. Use them freely in commercial software, databases, tokens, and any other application without attribution.
Why does the tool support uppercase and no-hyphens formats?
Some systems require specific formats: Microsoft's registry uses {UPPERCASE-WITH-HYPHENS-IN-BRACES}, MongoDB ObjectId-style APIs sometimes use lowercase without hyphens (32-char hex), and REST APIs typically use standard lowercase with hyphens. Pick whichever your target system expects.
Are my generated UUIDs private?
Yes — generation happens entirely in your browser. Nothing is uploaded, logged, or stored on any server. Even if you generate 1000 UUIDs and download them, none of them ever leave your device.
What's UUID v1 and why doesn't this tool have it?
v1 encodes the MAC address of the generating machine plus a timestamp — which leaks hardware information and creation time. It's discouraged for anything user-facing. v7 is the modern replacement for use cases where you want time-ordering without the privacy leak.

Related tools