Generate a GUID List Without Uploading Anything
Choose the batch size and representation, then use the generated table directly or download it. Random bytes come from the browser's cryptographic generator; no seed, UUID or list is sent to a remote service.
Generated UUIDs
| 1 | 0d50eeb5-4dc9-4e6a-8e06-b5da4c9498f4 |
| 2 | d5d20f67-03a7-48cc-aa69-4bb75d2ed5c8 |
| 3 | b3e99416-9a33-462b-b921-2412916e9371 |
| 4 | 7c0b6aa5-7f9d-4b15-8907-ef3f21627726 |
| 5 | 4e8b2480-3daf-42e7-8867-b49630334d80 |
| 6 | 6500c72a-42ad-4dda-ab59-9e5128c66dbe |
| 7 | 447e7d37-c3bb-4018-b37e-2b32a763a6f8 |
| 8 | a68311d7-727e-4907-ac26-aa0588800c47 |
| 9 | f5532feb-7e3a-404a-9054-3b8b46638e2c |
| 10 | 66a9c876-c25a-48f9-9892-bb6b6ae807b0 |
| 11 | d6ca40f8-3790-4343-9d9b-ad643ed44897 |
| 12 | d2624acd-b3e8-4f85-8199-315b97864ffb |
| 13 | 0924834c-7f63-444d-a341-bdd5ebfbc260 |
| 14 | 180a0829-4983-4788-a3ca-d8c9b91d7153 |
| 15 | 2085b625-6f98-4c07-9b1b-929397e87d40 |
| 16 | 51e45aac-3f52-4395-9e7c-a3a7698e0b34 |
| 17 | 4d96f8d8-57b4-4463-b998-7263ab5cdfa2 |
| 18 | 2798bfe3-b460-4b15-a45a-9b52b7141caf |
| 19 | d09e915b-b0f6-4bae-961d-b089f18bad33 |
| 20 | 1be5ada6-fba2-4a1d-ad4c-424317fb11c0 |
Results are provided as-is, with no warranty of accuracy. The method and its sources are published below so you can check the working.
The generator uses Web Crypto rather than Math.random.
Version and variant bits are set after all 16 random bytes are drawn.
Outputs are not placed in the address bar or stored as catalogue preferences.
How it works
How it is done
- 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.
- 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.
- 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.
- 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
Can a UUID v4 be used as a password or API secret?
Use a dedicated secret generator instead. UUID v4 exposes only 122 random bits and has a recognisable structure; identifiers and authentication secrets have different jobs.
Does uppercase change the UUID value?
No. Hexadecimal letters are case-insensitive. Uppercase and lowercase are only display choices for the same bits.
Sources
The full method, worked example and every assumption behind this figure are on UUID Batch Generator.