Tool
What the Secure UUID Generator does
Secure UUID Generator: generates UUIDs from How many. Example: how many 5 gives uuids c22d1c04-1d49-4a5a-ad92-fe5ee601fdf5 3f3c9a65-1bdf-4fc3-830e-d1444bed5581 48e8b553-edb8-4b35-a1eb-9e5429a85a65….
Give the Secure UUID Generator your How many and it works out UUIDs. Press the button when your inputs are ready and the result appears below.
Reusing a password is still the single most common way accounts fall over. The Secure UUID Generator exists to take that particular chore off your hands.
Nothing is transmitted or logged, which is the only acceptable design for a tool that handles credentials.
The field table, the method and a worked example are documented after the tool for anyone who wants to check the working.
What do the Secure UUID Generator fields mean?
The Secure UUID Generator uses 1 input. It opens with a complete example loaded, which is usually the quickest way to understand what a field means.
| Field | What to enter | Default |
|---|---|---|
| How many | accepts 1 to 50 | 5 |
How does the Secure UUID Generator work?
Each output is derived from the inputs above in a single pass; there is no hidden state carried between runs, so the same inputs always give the same generated output.
Each field is verified before use; failures are reported explicitly rather than swallowed.
Worked example
These are the values the Secure UUID Generator loads by default, and the result it produces from them. The numbers below come straight from the default inputs, so you can verify them against the live tool.
| How many | 5 |
|---|
| UUIDs | c22d1c04-1d49-4a5a-ad92-fe5ee601fdf5 3f3c9a65-1bdf-4fc3-830e-d1444bed5581 48e8b553-edb8-4b35-a1eb-9e5429a85a65… |
|---|
Why this is specifically a UUID version 4
Every UUID generated here is version 4: 122 random bits plus 6 fixed version/variant bits, produced by the browser’s CSPRNG (crypto.randomUUID when available). It carries no information about when or where it was created, which is the point.
| v1 (timestamp + MAC address | Not used here | Encodes creation time and network-card identity) a real privacy leak if exposed publicly |
|---|---|---|
| v4: random (this tool) | 122 random bits | No embedded information; collisions are purely a matter of chance |
| v5: namespace + name, SHA-1 | Not used here | Deterministic: the same name in the same namespace always produces the same UUID |
Worth knowing
- The collision odds for v4 are often illustrated as needing on the order of a billion UUIDs generated every second for roughly 85 years before there is a 50% chance of one collision: a commonly cited illustration of how sparse the 122-bit space is, not a guarantee for any specific application.
- Because v4 carries no timestamp or machine identifier, it is the right choice whenever you specifically do not want an identifier to leak anything about its origin. V1 is the wrong choice for anything public-facing for exactly that reason.
- If you need the same input to always produce the same identifier (deduplication by name, for instance), v4 is the wrong tool: that needs v5’s deterministic namespace hashing, not random generation.
Read next: Why We Run Everything in Your Browser
How to use it
- Set How many (1 to 50).
- Press Generate UUIDs.
- Check UUIDs on the right.
- To keep the result, either copy the link or print the page. Both preserve what is on screen.
What this tool does not do
- Randomness comes from your browser's cryptographic random source, which is suitable for passwords and keys.
- Anything generated here is only as safe as where you store it afterwards.
- The tool answers exactly the question it is given; it cannot know the context around your numbers.
- The tool trusts your numbers completely, so a mis-keyed digit propagates straight through.
Frequently asked questions
Only How many. Defaults are loaded for all of them, so nothing is mandatory before you see a result.
How many accepts 1 to 50. Go outside it and you get an error against that specific field instead of a misleading number.
With the values loaded when the page opens, uuids comes out as c22d1c04-1d49-4a5a-ad92-fe5ee601fdf5 3f3c9a65-1bdf-4fc3-830e-d1444bed5581 48e8b553-edb8-4b35-a1eb-9e5429a85a65…. Try changing one value. The answer refreshes without a page reload.
No record is kept. We never receive what you type, so there is nothing on our side to retain.
It is free with no conditions: no sign-up, and no limit on how often you use it.
It is accurate to the method shown. Rounding only affects what is displayed, never what is computed.