Generate cryptographically-random RFC 4122 v4 UUIDs. 100% local — no server calls.
UUIDs are generated locally using the browser's cryptographic random number generator (crypto.getRandomValues). No data is uploaded — everything runs in your browser. Generated UUIDs are collision-resistant for practical use but should not be treated as cryptographically authenticated identifiers.
About this tool
Generate cryptographically secure UUID v4s in bulk, instant and free. RFC 4122 compliant.
What Is the UUID v4?
The UUID v4 is a free browser-based developer tool that handles UUID v4 generator operations entirely on your device without any server round-trips. Built with standard web APIs and JavaScript, it processes your input locally — no code, data, or file content is ever uploaded to a remote server. The tool supports random UUID standards and handles edge cases like Unicode characters, special encoding modes, and large inputs. Performance is optimized for files up to 10MB+ using streaming parsers where applicable. Unlike online alternatives that require accounts or impose usage limits, this tool is completely free with no caps.
Who Should Use This Tool?
Software developers use this tool daily for UUID v4 generator tasks during coding, debugging, and deployment workflows. DevOps engineers rely on it for quick random UUID conversions when configuring servers or CI/CD pipelines. QA testers validate UUID generator outputs against expected values. Students learning web development use it as a reference tool to understand how encoding and formatting actually work. Technical writers format code examples for documentation. The tool is especially valuable in secure environments where corporate policy prohibits pasting code into external websites — everything stays local.
How to Use the UUID v4
Paste or type your input into the text area — the tool processes it instantly with no submit button needed. For UUID v4 generator operations, select your desired mode or options from the dropdown controls. The output panel shows results in real time with syntax highlighting where applicable. Use the copy button to transfer results to your clipboard. For batch operations, the tool handles multiple inputs separated by newlines. All processing happens in your browser's JavaScript engine — close the tab and your data is gone. Keyboard shortcuts (Ctrl+Enter) trigger the primary action for power users.
Frequently asked
Are the generated UUIDs cryptographically secure?
Yes. UUIDs are generated using the Web Crypto API (crypto.getRandomValues), producing RFC 4122 version 4 UUIDs with 122 bits of randomness. The collision probability is approximately 1 in 2^122 (5.3 × 10^36). Generate up to 10,000 UUIDs per batch, formatted as plain, JSON array, or SQL INSERT statements.
What output formats does it support?
Output options include: lowercase/uppercase plain text (one per line), JSON array, JavaScript array, SQL INSERT VALUES, and CSV. Bulk generation of 1,000 UUIDs completes in under 50ms. Each UUID follows the xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx pattern with version 4 and variant 1 bits correctly set.
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