🧬 Developer toolv1 – v8 · Nil · Max

UUID Decoder & Validator

Check whether a UUID or GUID is valid, find its version and variant, read the timestamp hidden inside v1, v6 and v7 UUIDs, and convert it to other formats.

Examples:
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Formats

Check a list

InputValidVersionCreated
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About the UUID Decoder & Validator

The UUID Decoder & Validator tells you what a UUID really is. Paste any UUID or Microsoft GUID, with or without dashes, braces or the urn:uuid: prefix. It checks the format, reads the version and variant bits, and for time-based UUIDs (versions 1, 6 and 7) shows the exact date and time the ID was created.

It also converts the UUID to uppercase, GUID, no-dash, URN, Base64, integer and byte formats, and can validate a whole list at once with a CSV export. Nothing is uploaded.

How to use it

  1. 1Paste a UUID or GUID into the top box, or tap an example.
  2. 2Read the result: valid or not, version, variant and, for v1, v6 and v7, the creation time.
  3. 3Copy the UUID in the format you need from the Formats table.
  4. 4To check many IDs, paste them into Check a list and download the CSV.

What it can do

✅
Strict validation

Explains exactly why an ID fails: length, characters, dash positions or an undefined version.

⏱️
Timestamp extraction

Reads creation time from v1, v6 and v7 UUIDs, in UTC and your local time.

🔁
8 output formats

Standard, uppercase, GUID braces, no dashes, URN, Base64, integer and bytes.

📋
Bulk check

Validate up to 10,000 UUIDs at once and export the results.

Frequently Asked Questions

How do I know which UUID version I have?

Look at the first digit of the third group: in 018f3c5e-7a2b-7c4d-… the 7 means version 7. This tool reads it for you and also checks the variant bits.

Can I get the creation date from a UUID?

Yes for versions 1, 6 and 7, which store a timestamp. Version 4 is fully random and versions 3 and 5 are hashes, so they contain no date.

Is a GUID the same as a UUID?

Yes. GUID is Microsoft's name for the same 128-bit identifier. GUIDs are often written in uppercase inside curly braces, which this tool accepts.

What are the Nil and Max UUIDs?

The Nil UUID is all zeros and the Max UUID is all f's. Both are special values defined by the standard, often used as placeholders.

Does a v1 UUID reveal my MAC address?

It can. Version 1 stores a node ID that is often the network card's MAC address. If the multicast bit is set, the node was generated randomly instead.