Enter 1–100 UUIDs to generate
Generate random UUID v4 (GUID) online, free. A UUID is a 128-bit universally unique identifier defined by RFC 9562 (which replaced RFC 4122). This tool generates version 4 UUIDs — 122 random bits plus version/variant markers — using the browser's built-in crypto.randomUUID (a cryptographically secure source), so each value is collision-resistant enough to use as a database key or distributed ID. Generate one or bulk-create up to 100 at once, entirely in your browser.
Every UUID is produced with crypto.randomUUID — the standards-based, cryptographically secure generator built into modern browsers — not Math.random, so values are safe to use as real identifiers. 100% free, no registration, and complete privacy — everything runs locally in your browser, so your data never touches a server.
v4 UUIDs come from crypto.randomUUID (a CSPRNG), giving 122 bits of randomness — far stronger and more collision-resistant than Math.random-based generators.
Generate one UUID or batch-create up to 100 at once for seeding tables, fixtures, or test data.
Copy a single UUID or the whole batch to your clipboard instantly — no manual selecting.
UUIDs are generated locally in your browser; nothing is uploaded, logged, or stored, and it works offline.
A version 4 UUID is generated from random data: 122 of its 128 bits are random, with the remaining bits fixed to mark the version (4) and variant. It's the most common UUID type because it needs no central coordination — any machine can generate one independently.
In practice, no. With 122 random bits there are about 5.3×10^36 possible values; you would need to generate billions of UUIDs per second for many years before a collision became likely. For virtually all applications they are safe to treat as unique.
Yes. They come from the browser's crypto.randomUUID, which uses a cryptographically secure random number generator — unlike Math.random-based tools. Note that 'secure to generate' doesn't make a UUID a secret; don't use one as a password or token where unpredictability must be guaranteed.
They're the same thing. GUID (Globally Unique Identifier) is Microsoft's name for a UUID; the 128-bit format is identical, so a v4 UUID generated here is a valid GUID.
UUID v7 embeds a timestamp so values sort roughly in creation order, which can improve database index locality. v4 is fully random and ideal when you don't need time-ordering. This tool generates v4; if your database supports v7 and you need sortable keys, prefer that at the database layer.
No. Generation runs entirely in your browser — nothing is sent anywhere, and the tool works offline.
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