Stackbench UUID Generator
Random v4 ids, sortable v7 ids and the all-zero NIL value, generated in your own tab from crypto.getRandomValues, with toggles for case, hyphens and the urn:uuid: form.
Nothing yet. Press Generate.
How to use
- Set how many ids you need in the How many field (1 to 1000; anything outside that is clamped and the status line tells you) and pick a version from the Version dropdown: v4 random, v7 time-ordered, or NIL.
- Press Generate. The plain list appears in the Output pane without line numbers, so it pastes straight into code.
- Adjust the Uppercase, Hyphens and Wrap as URN toggles to re-spell the same ids; the URN form keeps its hyphens, so that toggle is disabled while it is on.
- Press Copy to take the list with you, Download .txt to save it as uuids.txt, or Clear to empty the pane.
Frequently asked questions
Are these UUIDs safe to use as production keys?
The v4 and v7 values here are built from crypto.getRandomValues, the CSPRNG your operating system exposes to the browser, so they are not seeded from a clock or a weak pseudo-random generator. Each v4 carries 122 bits of randomness and each v7 carries 74. Collisions are a matter of probability, not of a weak generator; the status line names the entropy source so you can check.
Why does generating locally matter?
A key is only secret until it has been somewhere else. Online generators that build the id on a server put your identifiers, your table names and often your traffic in someone else’s logs. This page makes no request at all: the ids exist in your tab and nowhere else, and nothing is written to storage except your own display preferences.
When should I pick v7 instead of v4?
Choose v7 when the ids are a primary key. Its first 48 bits are the creation time in milliseconds, so new ids sort after old ones and a B-tree index stops jumping around the table; this tool also bumps the random field inside one millisecond, so a batch of v7s is strictly increasing. Choose v4 when nothing sorts by id, and NIL only as a placeholder.
Guides
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