UUID Generator
Generate universally unique identifiers (UUIDs).
Generate universally unique identifiers (UUIDs).
This free UUID Generator from KX Toolkit is part of our all-in-one online toolkit. It runs entirely in your browser, so your data never leaves your device for client-side operations. 100% free, forever - no paywall, no credit card, no trial.
How to use the UUID Generator
- Pick the algorithm or generation options.
- Enter your input (or click "Generate" for random output).
- Click the action button - the result appears instantly.
- Copy the result. Never paste sensitive secrets into the input again afterwards.
What you can do with the UUID Generator
- Generate strong passwords for new accounts.
- Hash data for verifying file integrity.
- Encode binary in Base64 for inline embedding.
- Test bcrypt or MD5 outputs while building auth systems.
Why use KX Toolkit's UUID Generator
- Browser-based: Works on Windows, macOS, Linux, iOS and Android - no install, no extension.
- Privacy-first: Client-side tools never upload your data; server-side tools delete files right after processing.
- Mobile-friendly: Full feature parity on phones and tablets - not a stripped-down view.
- Fast: Optimised for instant feedback. No artificial waiting screens, no email-gated downloads.
- One hub for everything: 300+ tools across SEO, text, image, PDF, code, color, calculators and more - skip switching between sites.
Tips for the best results
Always check the URL bar before pasting sensitive data - KX Toolkit's crypto tools run client-side, but you should still verify you're on the right domain.
Related Password & Encryption
If you find this tool useful, explore the full Password & Encryption collection or browse our complete tool directory. KX Toolkit is built for marketers, developers, designers, students and anyone who needs a quick utility without signing up for yet another SaaS.
What is the difference between UUID v1 and v4?
UUID v1 combines the current timestamp with the MAC address of the generating machine, which makes it sortable but reveals when and where it was generated. UUID v4 is purely random, providing 122 bits of entropy and no traceable metadata. v4 is the right default for almost every use case - distributed databases, request IDs, session tokens - unless you specifically need timestamp ordering or are interoperating with legacy v1 systems.
How likely are UUID collisions in practice?
For v4 UUIDs the probability is astronomically low. You would need to generate billions of UUIDs per second for decades to have a meaningful chance of one duplicate. In practice, you can treat them as unique forever for any realistic application. The collision math comes from the birthday paradox applied to a 122-bit random space, which yields a collision probability that exceeds the lifetime of typical hardware and software.
Can I use a UUID as a database primary key?
Yes, and many systems do. The tradeoff is storage size and index performance - UUIDs are 128 bits versus 32 or 64 for integer IDs, and random v4 UUIDs cause B-tree fragmentation because new rows insert in random positions. To get the best of both worlds, use UUID v7 (timestamp-prefixed) where supported, or store UUIDs as binary 16-byte columns rather than 36-character strings.
Why do UUIDs have hyphens and what format are they in?
The canonical text form is 8-4-4-4-12 hexadecimal characters separated by hyphens, totaling 36 characters. The hyphens have no semantic meaning - they exist purely for human readability. Most parsers accept both hyphenated and unhyphenated forms. The 32 hex characters represent 128 bits of data; the version digit at position 13 and a variant value at position 17 are reserved bits that identify which UUID scheme produced the value.
Is the UUID generated in my browser or on your server?
Locally in your browser. The tool uses crypto.randomUUID where available, falling back to a Web Crypto-based implementation in older browsers. Nothing is transmitted to our servers, so generated UUIDs never appear in any log we hold. You can generate as many as you like to seed a database or write into source code without leaving any trace of those values on our infrastructure.
Can UUIDs leak sensitive information?
v1 UUIDs encode the generator's MAC address and a high-resolution timestamp, which can deanonymize the source machine and reveal when it was generated. v4 UUIDs do not have this problem because they are pure random bytes. If you ever expose UUIDs to end users - in URLs, logs, or APIs - prefer v4 to avoid leaking infrastructure or timing details that an attacker could correlate.
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