Yes. UUIDs are generated in your browser using the Web Crypto API's cryptographically secure random number generator — the same CSPRNG used for TLS. No server is involved at any point.
Free Developer Tool — 100% In-Browser
UUID & GUID Generator
Generate cryptographically secure UUID v4 and v7 identifiers in bulk — or classic Microsoft GUID format with one click. Paste any UUID or GUID and instantly decode its version, variant, and embedded timestamp. Everything runs locally via the Web Crypto API: your identifiers are never uploaded, logged, or sent to any server.
- ✔ UUID + GUID formats
- ✔ Bulk generation (up to 500)
- ✔ Cryptographically secure
- ✔ 100% in-browser, never uploaded
- ✔ Decode any UUID or GUID
- ✔ Free Forever
Secure UUIDs & GUIDs, Generated 100% in Your Browser
Developers need these identifiers everywhere — database primary keys, API request IDs, distributed system trace IDs, .NET GUIDs, file names, and correlation tokens. This tool generates version 4 and version 7 UUIDs in bulk using the browser's built-in cryptographic random number generator (
crypto.getRandomValues), the same CSPRNG your browser
uses for TLS. Need classic Microsoft GUID style? One click gives you {UPPERCASE}
format, ready to paste into C#, SQL Server, or Active Directory code.
Because everything runs locally, it's safe to use for production identifiers — unlike most online generators, your UUIDs are generated by your machine and are never uploaded, logged, or shared. Paste any UUID or GUID into the Inspect tab and it decodes the version nibble, variant bits, and — for time-ordered versions (v1, v6, v7) — the embedded timestamp.
How It Works
1. Choose Quantity
Pick how many UUIDs you need, from 1 up to 500 at a time.
2. Pick Options
v4 or v7, uppercase, braces, no dashes — plus ready-made JSON arrays and CSV lists.
3. Generate
Every UUID is created by the Web Crypto API on your machine, never on a server.
4. Copy
Copy any format with one click, or inspect a pasted UUID to decode its metadata.
max 500
Paste any UUID or GUID — v1 through v8, with dashes, braces, or no dashes.
The tool decodes its version, variant, and embedded timestamp (for time-ordered
versions), and validates the format. All locally, nothing uploaded.
- Paste a UUID above and click Inspect…
Need Hashes or Secure Passwords Instead?
Generate SHA-256/512 hashes from text or files, or cryptographically secure passwords — all in your browser.
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UUID Reference
UUID Versions & Formats
| Version | Example | What it represents |
|---|---|---|
| v1 | 550e8400-e29b-11d4-... | Time-based — derived from the MAC address and a 60-bit Gregorian timestamp. Unique but leaks the generating machine's identity and time. |
| v3 | ...-3xxx-... | Name-based — MD5 hash of a namespace and name. Same input always yields the same UUID. |
| v4 | ...-4xxx-[89ab]... | Random — 122 random bits. The most common choice when you don't need ordering or reproducibility. |
| v5 | ...-5xxx-... | Name-based — same as v3 but using SHA-1, which is preferred today. |
| v6 | ...-6xxx-... | Time-based, reordered — a v1 with fields reordered so the timestamp reads naturally left-to-right, improving index locality. |
| v7 | 0189d0e0-78d4-7xxx-... | Time-ordered — 48-bit Unix millisecond timestamp followed by random bits. Ideal for database keys: sortable by creation time. |
| v8 | ...-8xxx-... | Custom — free-form, defined by the implementer. RFC 9562 reserves it for custom or experimental layouts. |
UUID vs GUID — what's the difference?
Practically nothing. GUID is Microsoft's term for a UUID; both are 128-bit identifiers. The classic GUID display style is uppercase with braces ({A3BB189E-8BF9-438A-A0F2-0C9F49B1F234}), which RFC 4122 permits — this tool offers it as a format option.
Are UUID v4 collisions a real risk?
No. With 122 random bits, you would need to generate about 2.6 × 10¹⁸ UUIDs before reaching even a one-in-a-billion chance of a collision. For any realistic workload, v4 collisions are impossible — which is why they're safe to use as database keys without checking for duplicates.
FAQsUUID & GUID Generator
Are the UUIDs generated by this tool truly random and secure?
Is my data uploaded anywhere?
No. All generation and decoding happens entirely in your browser. Nothing is sent to any server, and there is no registration.
What is the difference between UUID v4 and UUID v7?
UUID v4 is fully random. UUID v7 embeds a 48-bit Unix millisecond timestamp, so identifiers sort chronologically — which improves database index locality and makes v7 a better primary key. Use v4 when you want no timing information revealed.
Is it safe to use for production identifiers?
Yes. Because generation happens 100% in your browser, your UUIDs are never transmitted, logged, or stored on any server — there is no risk that a production identifier ends up in someone else's database.