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Free UUID Generator – v1 & v4 Online

Generate random UUIDs (v4) instantly. Bulk generation supported.

Updated Dec 06, 2025

Generate UUIDs
Select version and quantity to generate.

Identifiers

Generate trustworthy UUIDs in your browser

Universally Unique Identifiers (UUIDs) offer collision-resistant IDs without central coordination. This generator supports v1 (time-based) and v4 (random) UUIDs, lets you copy batches instantly, and never uploads values to a server.

Pick the right version

Version 4 UUIDs use cryptographically secure randomness, making them ideal for databases, API requests, or test data. Version 1 UUIDs include timestamps and node identifiers, which means they are sortable and easier to trace. The generator helps you choose based on your use case and explains the trade-offs inline.

Need namespace-based UUIDs (v3/v5)? Provide a namespace plus a name string and we will hash them deterministically, giving you stable IDs for schema registries or caching layers.

  • Batch export

    Generate dozens of UUIDs at once and copy them as JSON, newline lists, or array literals.

  • Validation helper

    Paste existing IDs to verify they conform to the version you expect before trusting user input.

Fast iteration for any team

Because everything runs locally, sensitive identifiers never leave your device. Use the tool on air-gapped VMs, staging servers, or presentation machines without worrying about network traffic.

Annotate batches with commit hashes or ticket IDs so you know which UUIDs seeded fixtures, migrations, or integration tests. This simple habit saves hours when chasing down mismatched records later.

  • Checksum friendly

    Optionally uppercase values or remove dashes to match platforms with strict formatting requirements.

  • Clipboard guardrails

    Automatic success banners confirm when IDs are copied, reducing the risk of off-by-one mistakes when pasting into databases.

Where UUIDs shine

Distributed systems

Generate IDs on each node without round-trips to a central authority.

Test data

Seed fixtures with realistic identifiers that never collide between test runs.

Client-generated keys

Let mobile or IoT devices create request IDs even when offline.

Event tracing

Attach UUIDs to log entries so you can correlate events across services.

Next step

Need to encode or share the IDs?

After generating UUIDs, jump into the Base64 Encoder or QR Code Generator to transmit them through constrained channels.

Open Base64 Encoder

Popular combinations

Frequently asked questions

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit label used for information in computer systems. It is designed to be unique across all systems and all time, making it perfect for database keys and session IDs.

Are these UUIDs truly unique?

Yes. We generate Version 4 UUIDs, which are based on random numbers. The probability of a collision (generating the same UUID twice) is astronomically low—so low that it can be effectively ignored for all practical purposes.

How many UUIDs can I generate?

You can generate up to 1000 UUIDs at once with this tool. If you need more, simply click the generate button again.

Do you store the generated UUIDs?

No. All UUIDs are generated locally in your browser using JavaScript's crypto API. We do not track or store them.

How to use Free UUID Generator – v1 & v4 Online

Follow these four quick steps to produce repeatable identifiers or assets right inside your browser—no downloads, no accounts, and no data leaving the FreeTools.run sandbox.

  1. Step 1: Load your source data

    Paste text, drag a file, or start with our curated sample to understand how the generator workflow behaves with real inputs.

  2. Step 2: Adjust tool options

    Toggle presets, update formatting rules, or choose export preferences. All controls update in real time so you can preview the effect before committing.

  3. Step 3: Review the live preview

    Use the split-pane preview, inline validation, or diff output to confirm the transformation looks correct before you copy anything back into your project.

  4. Step 4: Export or chain another tool

    Copy the result, download a file, or jump into a related FreeTools.run utility (like Diff Checker or the QR Code Generator) to continue the workflow without leaving the browser.

Free UUID Generator – v1 & v4 Online | FreeTools.run | FreeTools.run