v4 random
122 random bits via crypto.getRandomValues(). RFC 4122 compliant, practically collision-proof.
UUID v4 · UUID v7 · Bulk · No upload · Browser
Free UUID v4 / v7 Generator
Generate UUID v4 (random) and v7 (timestamp-sortable) identifiers directly in your browser. Choose quantity, format, separator. Validate and inspect existing UUIDs. No data ever leaves your device.
Generated UUIDs
UUIDs to inspect
Paste a UUID to inspect it.
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Key features
v7 timestamped
48-bit Unix ms prefix + random bits. Chronologically sortable, ideal for primary keys.
Combinable formats
Case + dashes + wrapper are independent. Add a custom prefix. Export TXT, JSON, CSV.
Live validation
Version detection, ISO timestamp extraction for v7, RFC 4122 variant check. Accepts dashed and no-dash formats.
Frequently asked questions
What is the difference between UUID v4 and v7?
UUID v4 is fully random (122 bits). UUID v7 encodes the first 48 bits with a Unix millisecond timestamp, making it sortable in a database without a secondary index.
Can I combine uppercase and no-dashes?
Yes. Case, dashes and wrapper are three independent options. For example: UPPER + no dashes gives F47AC10B58CC4372A5670E02B2C3D479.
Can I use the no-dashes format in a database?
Yes. CHAR(32) without dashes is supported by MySQL, PostgreSQL and SQLite. The dashed format (CHAR(36)) is the most common and recommended for readability.
What does the custom prefix do?
It adds a text prefix before each UUID, for example id_ or user_. Useful for generating identifiers ready to paste into code.
Does the tool work offline?
Yes. Once the page is loaded, everything runs in the browser with no network requests. Generation uses the browser's native crypto API.