Online Tool Store
GUID Generator
Generate version 4 GUIDs in bulk, formatted for Windows registry keys, code, or config files, with case, braces, and hyphens all optional. Runs in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Latest GUID
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Click any GUID to copy it on its own.
How it works
- Choose how many you need — one, or up to 500 at a time.
- Pick a preset, or set case, wrapper, and hyphens yourself.
- Click any GUID to copy it, or take the whole list at once.
- Generate again for a fresh batch; nothing is stored between runs.
What the 32 characters are made of
A GUID is 128 bits written as 32 hexadecimal digits. Not all of them are random — two small fields are fixed so that anything reading the value knows what kind of GUID it is:
bed4e80f-9af3-4146-836f-6c4dfc63762b
↑ version — always 4 here
↑ variant — always 8, 9, a, or b
That leaves 128 − 4 − 2 = 122 genuinely random bits, or about 5.3 × 10³⁶ distinct values. The scale is what makes GUIDs useful: two machines with no knowledge of each other can each invent identifiers all day and never clash, so you never need a central counter handing out IDs.
Version 4 is the all-random kind, and it is what you almost always want. Other versions build the value from a timestamp and the machine's network address, which makes them sortable but also predictable — and historically a quiet way of leaking which machine created a record.
Formatting is presentation only
The braces, the hyphens, and the letter case carry no information. All four of these are the same identifier:
bed4e80f-9af3-4146-836f-6c4dfc63762b // canonical
{BED4E80F-9AF3-4146-836F-6C4DFC63762B} // Windows registry
bed4e80f9af34146836f6c4dfc63762b // compact, 32 chars
(bed4e80f-9af3-4146-836f-6c4dfc63762b) // parenthesised
Worth knowing when comparing GUIDs in code: a string comparison of two differently-formatted GUIDs will say they are different when they are not. Strip the punctuation and normalise the case before comparing, or compare the parsed values rather than the text.
FAQ
Is GUID the same thing as UUID?
Yes, in practice. GUID is Microsoft's name for it and UUID is the name in the standard, but they describe the same 128-bit identifier. The difference you will actually notice is formatting convention: Windows tends to write them uppercase inside braces, while most other ecosystems use lowercase without.
Are these generated on a server?
No. They come from your browser's own cryptographic random number generator, so nothing is requested or logged, and the same GUID is never seen by anyone else — including us.
Could I ever get a duplicate?
Not realistically. A version 4 GUID carries 122 random bits, which is about 5.3 × 10³⁶ possibilities. You would need to generate billions per second for longer than the universe has existed before a collision became likely, which is why they are safe to create independently on different machines with no coordination.
Why is there always a 4 in the same position?
That digit is the version number, and it is fixed rather than random. Along with the variant bits just after it, it tells anything reading the GUID how it was generated — so those few bits are deliberately not random, which is why the total space is 2¹²² rather than 2¹²⁸.
Which format should I use where?
Uppercase inside braces for Windows registry keys, COM class IDs, and .NET config. Lowercase with hyphens for databases, JSON, and most APIs. Without hyphens when a system limits the field length or dislikes punctuation — the value is identical either way, only the presentation changes.
Can I use a GUID as a secret or a password?
For a random token, a version 4 GUID is genuinely unguessable, so it works as an unguessable URL or an API key. Do not treat every GUID that way, though: other versions encode a timestamp and machine identifier, so they are predictable and were never designed to be secret.
How we compare
| Feature | Online Tool Store | Server-side GUID sites | Your own terminal |
|---|---|---|---|
| Generated on your device, seen by nobody else | ✓ | ✗ | ✓ |
| Windows, compact, and custom formats | ✓ | Often canonical only | Pipe it through sed yourself |
| Bulk generation with one click | ✓ | ✓ | A loop, if you remember the syntax |
| No ads, no rate limit | ✓ | ✗ | ✓ |
| Other GUID versions (1, 5, 7) | ✗ | Some offer them | ✓ |
Useful when you need an identifier right now in the exact shape a config file or registry key wants, without an ad break or a server involved. It does version 4 only — the all-random kind you almost always want; timestamp-based versions are a job for a library.