DevCoreTools

UUID Validator / Inspector

Paste one or many UUIDs to validate format, inspect version and variant, and identify malformed identifiers.

UUID input

Use one UUID per line, or paste comma and space separated values.

Processed locally in your browser Limit browser memory. Your input is processed in your browser and is not uploaded or sent to a server. Avoid pasting production secrets, access tokens, private keys, passwords, or sensitive customer data unless you understand the risk.

Inspection result

Normalized output, version, variant, format, casing, and warnings.

Ready to inspect UUIDs

Paste UUID or GUID values on the left, then validate to see canonical form, version, variant, duplicate, and formatting details.

UUID Validation Guide

Validate and inspect existing UUID values

Use the UUID Validator / Inspector when you already have identifiers from logs, APIs, databases, fixtures, or bug reports and need to check their shape without generating new values.

Canonical UUID format

The canonical text format is 36 characters with hyphens after the 8th, 12th, 16th, and 20th hexadecimal digits. Compact 32-character values can be valid, but many APIs expect canonical hyphenation.

UUID versions

The version nibble identifies layouts such as v1 time-based, v3 and v5 name-based, v4 random, and newer v6 or v7 time-ordered formats when the value uses those version bits.

UUID variants

The variant bits identify the UUID layout family. Most modern application UUIDs use the RFC 4122 and RFC 9562 variant; other bit patterns are compatibility or reserved forms.

GUID vs UUID

GUID is often used in Microsoft ecosystems, while UUID is the standards term. In everyday developer workflows they usually refer to the same 128-bit identifier text format.

Validator vs generator

The UUID Generator creates new random UUID v4 values. This validator inspects UUIDs you already have, normalizes casing and hyphens, and explains malformed or unusual identifiers.

Identifiers, not proof

UUIDs are useful identifiers, but they are not passwords, signatures, or cryptographic proof. Treat them as record IDs and avoid using UUID syntax alone as an authorization check.

UUID Validator FAQ

Can this validate multiple UUIDs at once?

Yes. Paste one UUID per line or paste values separated by commas, spaces, or tabs. The report keeps each token as a separate inspected row.

Are uppercase GUIDs invalid?

No. Uppercase hexadecimal letters are valid UUID text, but lowercase canonical formatting is common in APIs, databases, and logs.

Is a no-hyphen UUID valid?

A 32-character hexadecimal UUID can represent a valid identifier. The tool warns because canonical UUID text includes hyphens and is easier to read safely.

What are nil and max UUIDs?

The nil UUID is all zeroes, and the max UUID is all f characters. They are valid syntax, but they usually represent boundary or sentinel values rather than normal records.

Does validation prove a UUID exists?

No. Syntax validation only confirms the identifier is shaped like a UUID and reveals its version and variant bits. It cannot prove that a database row, API resource, or event exists.

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