UUID Validator
Paste one UUID or a whole list and see instantly which are valid. For each one you get the version (v1–v8), the variant and — for time-based v1, v6 and v7 UUIDs — the exact date and time it was created.
Results appear here as you type.
What Makes a UUID Valid?
Format, variant and version — all checked here.
A UUID (also called a GUID) is a 128-bit identifier written as 32 hexadecimal digits in five groups: 8-4-4-4-12, for example 017f22e2-79b0-7cc3-98c4-dc0c0c07398f. Upper and lower case are both allowed.
Two digits carry meaning. The first digit of the third group is the version — how the UUID was made (4 = random, 7 = time-ordered, and so on). The first digit of the fourth group shows the variant: 8, 9, a or b means a standard RFC 9562 UUID.
Valid, non-standard, invalid. Valid means the correct format, the standard variant and a version from 1 to 8 — or the special Nil (all zeros) and Max (all f) UUIDs. Non-standard means the format is right but the variant or version isn't one defined by RFC 9562 (e.g. very old Microsoft GUIDs). Invalid means it isn't a UUID at all — wrong length, wrong characters or misplaced hyphens.
Hidden timestamps. v1 and v6 UUIDs contain a timestamp in 100-nanosecond steps since 15 October 1582; v7 UUIDs start with a Unix timestamp in milliseconds. The validator decodes them, so you can see when a record was created.
UUID Versions
The digit after the second hyphen.
| Version | How it's made | Shown here |
|---|---|---|
| 1 | Timestamp + node (often a MAC address) | Date & time, node |
| 2 | DCE Security (rare) | — |
| 3 | MD5 hash of a namespace + name | — |
| 4 | Random — the most common | — |
| 5 | SHA-1 hash of a namespace + name | — |
| 6 | Reordered v1, sortable by time | Date & time, node |
| 7 | Unix milliseconds + random — sortable, recommended for databases | Date & time |
| 8 | Custom / vendor-specific layout | — |
| Nil / Max | 00000000-…-000000000000 / ffffffff-…-ffffffffffff | Special values |
How to Use the UUID Validator
Get your result in under ten seconds.
Paste your UUIDs
One per line — from a database export, logs or code.
Read the table
Status, version, variant and creation time for each one.
Export
Copy or download the results as CSV.
Why Use the UUID Validator on Developers Web Tools
Fast, accurate and private — built for developers.
Three-level result
Valid, non-standard or invalid — with the reason.
Every version
v1 to v8 from RFC 9562, plus Nil and Max.
Timestamps
Creation date and time decoded from v1, v6 and v7.
Bulk check
Thousands of lines at once, with a CSV export.
Flexible input
Braces, urn:uuid: and hyphen-less forms — or strict mode.
Private
Your IDs never leave the browser.
Frequently Asked Questions
Look at the first digit of the third group: in xxxxxxxx-xxxx-4xxx-… it's 4, a random UUID. The validator shows it for every line.
Yes. GUID is Microsoft's name for the same 128-bit format. Windows tools often show it in braces, {…}, which this validator accepts unless Strict format is on.
Only for time-based versions. v1 and v6 store a timestamp with 100-nanosecond precision, and v7 stores Unix milliseconds — the validator shows them in UTC. v4 UUIDs are random and contain no time.
Its format is correct, but the variant digit (first digit of the fourth group) isn't 8, 9, a or b, or the version digit isn't 1–8. Such IDs still work as unique keys in most systems, but they weren't generated according to RFC 9562.
Yes. RFC 9562 says UUIDs should be written in lowercase but must be accepted in any case.
No. Validation runs entirely in your browser.