Bulk-generate random v4 and time-ordered v7 UUIDs in your browser with count and format options. Copy or save as text.
What each field means and how to use it. Click to expand.
v4 is a fully random UUID with 122 bits of randomness. v7 is time-ordered, carrying a 48-bit Unix millisecond timestamp in its first bits so values increase monotonically. Random v4 primary keys can fragment indexes, so v7 is increasingly preferred for databases.
How many to generate at once (1-1000). Handy for test data or seed inserts; bulk-generate and save as .txt.
Combine uppercase, hyphen removal and brace wrapping. Braced form (e.g. {550e8400-...}) is used by some Microsoft-style GUID notations. Choose what fits your target.
Randomness comes from crypto.getRandomValues (cryptographically secure). For v4 the tool uses crypto.randomUUID when the browser supports it. Results are shown only on the page and never sent to a server.
v4 is fully random; v7 is time-ordered with a leading timestamp. Because v7 sorts in creation order, it tends to help database primary keys and indexes.
With 122 bits of randomness the practical collision probability is extremely low, but where uniqueness is critical, pair it with a database unique constraint.
No. Generating, copying and saving all happen in your browser, and results are never sent.