UUID Tools API
Free UUID generator API with no key. Generate v1, v3, v4 and v5 UUIDs in bulk over HTTP. Tested curl example, live response and guidance on when to use it.
Endpoint tested and returned HTTP 200 on 19 Aug 2026
What is the UUID Tools API?
The UUID Tools API is a free HTTP endpoint that generates universally unique identifiers on demand. It supports UUID versions 1, 3, 4 and 5, can return many at once, and requires no API key.
This API generates RFC 4122 UUIDs over plain HTTP with no key, which is handy in shell scripts, CI pipelines and low-code tools where you have an HTTP client but no UUID library at hand.
One honest caveat belongs on this page: for application code you should generate UUIDs locally with `crypto.randomUUID()`, Python's `uuid` module or your language's equivalent. A network round trip for a value you can compute instantly adds latency and a failure mode for no benefit. Use this API for scripting and testing, not in a request path.
Quick facts
- Base URL
https://www.uuidtools.com/api- Authentication
- No key required.
- Rate limit
- No published limit; intended for light scripted use.
- Pricing
- Free.
- CORS
- Enabled — callable directly from browser JavaScript
- Official docs
- Read the docs
How to use the UUID Tools API
Every request below was executed against the live API on 19 Aug 2026, and the response shown is the real body it returned — not an illustration.
1. Generate a random v4 UUID
GET https://www.uuidtools.com/api/generate/v4
curl 'https://www.uuidtools.com/api/generate/v4'const res = await fetch("https://www.uuidtools.com/api/generate/v4");
if (!res.ok) throw new Error(`Request failed: ${res.status}`);
const data = await res.json();
console.log(data);import requests
res = requests.get("https://www.uuidtools.com/api/generate/v4", timeout=20)
res.raise_for_status()
print(res.json())[
"95758775-d418-430c-a4f4-d1bf98129452"
]Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
<version> | path | Required | v1, v3, v4 or v5. v4 |
<count> | path | Optional | How many to generate in one call. 10 |
Response fields
(array)array- A JSON array of UUID strings; a single-element array even when you request one.
What you can build with the UUID Tools API
- Generate correlation ids in shell scripts and CI jobs
- Create test fixtures needing many unique identifiers at once
- Produce UUIDs in low-code and automation platforms without a code step
- Demonstrate UUID formats and versions when teaching
Common errors and how to fix them
404
Unrecognised version path.
Fix: Use v1, v3, v4 or v5 exactly, lowercase and prefixed with v.
Network failure blocks your app
You put a network call on the critical path for something computable locally.
Fix: Generate UUIDs in-process with crypto.randomUUID() or an equivalent library.
UUID Tools API — frequently asked questions
Should I use an API to generate UUIDs?
Only for scripting, testing or low-code tools. In application code, generate them locally — `crypto.randomUUID()` in JavaScript or the `uuid` module in Python — because a network call adds latency and a failure mode for a value you can compute instantly.
What is the difference between UUID v1 and v4?
v1 is derived from timestamp and MAC address, making it sortable but potentially revealing host information. v4 is random, which is the right default for identifiers you expose publicly.
Can I generate several UUIDs in one request?
Yes, append a count to the path, for example /api/generate/v4/10 for ten identifiers in a single response.
Are UUIDs from this API cryptographically secure?
Treat them as unique, not secret. Never use a UUID as a session token, password reset token or API key — use a cryptographically secure random generator designed for secrets.
Tools that pair with this API
UUID Generator
Generate 1–100 cryptographically random UUID v4 identifiers at once. Uppercase and hyphen-less options, per-item copy and copy-all. Free UUID generator.
Password Generator
Generate strong random passwords with cryptographically secure randomness. Choose length and character sets, see entropy strength, copy instantly.
JSON Formatter
Format, beautify and minify JSON online with 2-space, 4-space or tab indentation. Sort keys alphabetically and catch syntax errors instantly — free and private.
Alternatives to UUID Tools API
If UUID Tools API does not fit, these developer & testing apis cover similar ground. Every one was called before publishing, and each links to its own reference page with a working curl command and the response it returned.
| API | What it does | Auth | CORS | Last verified |
|---|---|---|---|---|
| GitHub REST API | GitHub REST API with no key for public data: repository details, users, issues, releases and commits. 60 req/hour unauthenticated, 5,000 with a token. | No key | Yes | 19 Aug 2026 |
| JSONPlaceholder | Free fake REST API for testing and prototyping. Posts, comments, users and todos with full GET, POST, PUT and DELETE support. No key. Real curl examples. | No key | Yes | 19 Aug 2026 |
| Postman Echo | Postman Echo reflects your HTTP request back as JSON: headers, body, query params and auth. Free, no key, ideal for debugging clients. Real POST example. | No key | No | 19 Aug 2026 |
| DummyJSON | Free fake REST API with realistic products, users, carts, recipes and auth. Supports search, pagination, sorting and POST. No key. Tested GET and POST examples. | No key | Yes | 19 Aug 2026 |
| Vector Express | Convert between SVG, DXF, DWG, EPS, PDF, AI, CDR, HPGL and more over HTTP with no key. Query the converter matrix first to find a valid conversion path. | No key | No | 21 Aug 2026 |
| W3C API | Query W3C for specifications, working groups, editors and publication history as HAL+JSON. No API key. Verified example plus a guide to following HAL links. | No key | Yes | 21 Aug 2026 |
UUID Tools API is an independent third-party service and is not affiliated with ByteTools or ByteVancer. Details on this page were verified on 19 Aug 2026; always check the official documentation before relying on this API in production, as terms and limits can change.