UUID Validator/Decoder

How to Use the UUID Validator/Decoder

1. Paste one UUID or a list of UUIDs into the input box. The tool accepts canonical UUIDs, GUIDs with braces, URN UUIDs, and compact 32-character hexadecimal strings.
2. If you are checking a UUID v5 value, choose the namespace and enter the name string to verify whether that namespace/name pair generates the pasted UUID.
3. Click Validate & Decode UUID to parse the UUID layout, version, variant, normalized formats, and any version-specific metadata.
4. Use the colored field map and metadata rows to inspect timestamp, node, random payload, deterministic hash behavior, and validation warnings.

UUID Versions Explained

What the Decoder Checks

• Canonical grouping, compact hexadecimal UUIDs, braced GUIDs, and URN UUID syntax.
• Version nibble, variant bits, and the standard RFC 4122 layout used by v1, v4, and v5 UUIDs.
• UUID v1 timestamp conversion to UTC, clock sequence, node value, and privacy indicators.
• UUID v4 randomness layout and UUID v5 deterministic namespace/name verification.
• Normalized output formats for copying into code, databases, logs, and API tests.

FAQ

What is a UUID?

A UUID is a 128-bit identifier commonly written as 32 hexadecimal characters grouped 8-4-4-4-12. Different UUID versions use those bits for different purposes, such as time-based IDs, random IDs, or namespace/name hashes.

Can a UUID v1 reveal a MAC address?

Sometimes. UUID v1 stores a 48-bit node value. If the multicast bit is not set, that node may be derived from a hardware MAC address; if the multicast bit is set, it was probably generated as a random or privacy-preserving node.

Can a UUID v4 creation time be decoded?

No. UUID v4 does not contain a timestamp, node, or machine identifier. It stores 122 random bits plus fixed version and variant bits, so a validator can inspect the layout but cannot recover when or where it was created.

What can be decoded from UUID v5?

UUID v5 records that the ID was created from a SHA-1 namespace/name hash, but it does not reveal the original namespace or name. If you already know those source values, this tool can recompute the UUID and check whether they match.

Is uppercase or compact UUID input valid?

Yes. Uppercase UUIDs, braced GUIDs, URN UUIDs, and compact 32-character hexadecimal UUIDs can all be valid. The decoder normalizes valid input into canonical lowercase UUID format.