UUID Generator
Generate version 4 (random) or version 7 (time-ordered) UUIDs, also called GUIDs, up to 10,000 at a time, in upper or lower case, with or without hyphens. Check any UUID's version and time.
122 random bits: the usual choice.
Check a UUID
How to use it
- 1Choose version 4 (random) or version 7 (time-ordered), and how many you need.
- 2Pick a format if you need one: UPPERCASE, without hyphens, or in braces { }.
- 3Copy them, or download them as a .txt file with one on each line. Press Generate again for new ones.
- 4To check a UUID, paste it under Check a UUID to see its version, its variant and the time inside it.
Frequently asked questions
What is the difference between UUID v4 and v7?
Version 4 is 122 random bits. Version 7 starts with the time in milliseconds, followed by random bits, so newer UUIDs sort after older ones. That makes v7 better as a database key: new rows go to the end of the index instead of anywhere in it.
Are these UUIDs really unique?
For all practical purposes, yes. They come from your browser's cryptographic random number generator: with 122 random bits, you could make a billion v4 UUIDs every second for 85 years before a repeat became likely. Version 7 UUIDs from this page also keep increasing within the same millisecond.
Is a UUID the same as a GUID?
Yes. GUID is Microsoft's name for a UUID. Windows tools often write them in capitals and in braces, like {6F9619FF-8B86-D011-B42D-00C04FC964FF}: tick UPPERCASE and With braces to get that form.
How many UUIDs can I make at once?
Up to 10,000 at a time. They're made on your device, so nothing is sent to a server and no one else ever sees them.
Can I tell when a UUID was made?
For versions 1, 6 and 7, yes: the time is inside the UUID. Paste it under Check a UUID to see that time in your time zone. Version 4 UUIDs are random and hold no time.
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