What is the difference between UUID v4 and v1?
v4 is random with extremely low collision risk for general IDs. v1 is time-based with node information—useful when chronological ordering matters.
UUID Generator
DevTools UUID Generator creates UUID v4 (random) or v1 (timestamp) identifiers locally in your browser with batch output and one-click copy—free with no sign-up.
UUID Generator
Generate UUID v4 (random) or v1 (timestamp) identifiers with batch output and one-click copy.
UUID
5a49cea0-79fa-4128-abf4-7483b820ff89
About this tool
UUIDs are used for database keys, distributed IDs, and API tracing. v4 is random for general use; v1 embeds time for sortable IDs.
How to use
- Choose UUID version (v4 or v1).
- Set batch count (1–100).
- Click Regenerate and copy results.
FAQ
Are generated UUIDs sent to a server?
No. UUIDs are created locally via the Web Crypto API.
Are UUID and GUID the same?
In practice, yes. GUID is Microsoft's name for the same identifier format.
Is this tool free?
Yes. No registration required.
Related tools
- Converters
Convert between common formats: CSV/JSON, YAML/JSON, TOML/JSON, Markdown/HTML, timestamps, image Base64, text encodings, and number bases.
- Formatter
Format and beautify SQL, HTML, XML, and YAML, plus a regex debugger—all run locally in the browser, free with no sign-up.
- JSON Tools
Full JSON toolkit: format, validate, minify, convert to CSV/XML, diff, generate and validate Schema, JSONPath, and tree view—all processed locally in the browser.
- Favicon Generator
Upload a logo, preview browser and Google search results, configure iOS/Android icons, and generate a complete favicon package in one click.