What is the UUID v4 Generator?
Generate a cryptographically-random UUID v4. Uses the browser's secure random source — generated locally, never logged.
The tool is part of the Calabi free tools hub — a collection of 99+ browser-based utilities for developers, designers, and content creators. Everything runs client-side: your files and data never leave your device.
How to use the UUID v4 Generator
- Step 1: Click Generate for a fresh UUID.
- Step 2: Copy it.
- Step 3: Generate again for another.
The tool updates in real time as you interact with it. No button-clicking required for most tools — results appear instantly.
Example
→ 3f50b2e1-9c4a-4f7b-8a2d-1e6c9b0a7d4f
Privacy & security
The UUID v4 Generator is designed with privacy as a hard constraint, not an afterthought:
- No upload: Your data is processed in your browser's JavaScript engine. No HTTP request is made to any server while you use the tool.
- No account required: The tool works instantly — no email, no sign-up, no cookie consent wall.
- No logging: Calabi does not log what you paste, upload, or generate. The server only delivers the HTML/JS page — it never sees your content.
- Open to inspection: Open your browser's network inspector while using the tool. You'll see zero outbound requests related to your data.
This architecture is particularly important for the Generators category of tools, where the inputs often contain sensitive or proprietary information.
Frequently asked questions
Is the UUID v4 Generator free?
Yes, completely free with no account required.
Does it upload my data?
No. The UUID v4 Generator runs entirely in your browser — your data never leaves your device.
Will it work on mobile?
Yes. The tool works on any modern browser on desktop and mobile.
Can I use this for commercial purposes?
Yes, there are no restrictions on commercial use.
About Generators
The UUID v4 Generator is part of the Generators category in the Calabi tools hub. Generate a random RFC-4122 version-4 UUID in your browser using the secure Web Crypto API. All tools in this category run entirely in your browser with no server involvement.