Menu

Search toolsChangelog

to move to openDescribe the problem, not the tool

Generate 100 UUID v4 Values at Once

Set the quantity to 100 and keep the canonical representation for the familiar 8-4-4-4-12 layout. Each row is generated from fresh Web Crypto bytes, with the version nibble fixed to 4 and the variant bits fixed to RFC 9562's 10 pattern.

One to 10,000 independent version 4 UUIDs. The table can be copied or downloaded as CSV.

The underlying 128 bits are the same. Only their text representation changes.

UUIDs generated
100
Random bits in each UUID
122
Duplicates in this batch
0
Representation
Canonical, lowercase

Generated UUIDs

1060d00db-49a0-41fa-8a24-b8839212d4a8
2b651b336-cec7-4963-b649-def72100f61b
3433476e4-c366-4bbf-a92a-d65ac67b55e9
415ca144d-6e5e-469a-b5d7-0505667a4e16
54b440e6b-8d29-439d-b018-0604c3ca7e87
680233c84-ad78-488a-b427-2096e345090e
7119e0bd4-140f-4be2-b860-d67dce4f4dfe
8a9d5b11e-18ba-418e-9d86-f8a7fa954bdc
977090ecb-45bf-495f-b189-af99dc367776
10699a65d6-5c46-476d-8d36-400e147d9e8d
11cdcfff20-24e3-4f73-b2ee-0c3482d9ffc6
1297defa60-78de-48a4-8edf-d25997757941
13ea014783-b8a7-4f9e-a737-8d29c677818f
145b67822b-4b48-40bd-9e00-d09b8d76fc35
1583aff543-da33-4b68-a6b6-010d932e202c
16bf214645-d4e0-4f15-bd18-410b0560c015
173a842dbb-0e58-412b-b04d-dbdf8b6a6487
184d4692d3-dafd-4406-8aca-728f7b2d5476
194a5cddc6-8600-41b9-8e7a-6db1af9814ea
207a44f0d8-e291-4e60-a5e3-a29edba5817c

Results are provided as-is, with no warranty of accuracy. The method and its sources are published below so you can check the working.

What to take away
  1. Every UUID has 122 random bits after the version and variant fields are set.

  2. Canonical, compact and URN choices are text representations of the same UUID bytes.

  3. The complete batch renders as a table that can be downloaded as CSV.

How it works

How it is done

  1. Validate a whole-number batch size from 1 to 10,000. Allocate 16 bytes per UUID and fill them from Web Crypto in calls no larger than its 65,536-byte quota.
  2. In octet 6, preserve its low four random bits and replace the high four with 0100, the version 4 field. In octet 8, preserve its low six random bits and replace the high two with 10, the RFC variant.
  3. Render the 16 octets as 32 hexadecimal digits. Canonical form inserts hyphens in the 8-4-4-4-12 grouping; compact removes them; URN adds the urn:uuid prefix. Letter case changes no bit.
  4. Compare canonical values inside the current batch and report any duplicate actually observed. Render every value as a static result row that can be copied or downloaded as CSV.

What it assumes

  • Each UUID starts from browser cryptographic random bytes, not Math.random and not a user-visible seed. Six structural bits leave 122 random bits per value.
  • Random UUIDs make collisions extraordinarily unlikely; they do not make a mathematical uniqueness guarantee. The batch duplicate count is an observation, not proof against a value generated elsewhere.
  • UUIDs are identifiers, not authentication secrets. RFC 9562 says not to assume they are hard to guess or use mere possession as an access capability.
  • The generated values are not placed in the URL, saved to catalogue preferences or sent to a server. Recomputing intentionally produces a new batch.

Common questions

Are 100 UUID v4 values guaranteed to be unique?

No random identifier system can promise that, but a collision in a batch of 100 drawn uniformly from 122 random bits is extraordinarily unlikely. The result also checks the batch and reports any duplicate it actually contains.

Is a GUID different from a UUID?

GUID is Microsoft's common name for the same 128-bit identifier family. The canonical text layout produced here is accepted in both contexts.

Sources

The full method, worked example and every assumption behind this figure are on UUID Batch Generator.