Inspect GUID / UUID
Paste any GUID / UUID to detect, decode and decompile its version, variant, timestamp (Unix milliseconds / ISO time), RFC variants, Node Identifier (Possibly MAC-address derived) if relevant, embedded fields (time_low, time_mid, time_hi_and_version, clock_seq_hi_and_reserved, clock_seq_low, node), Security warnings and helpful notes.
This inspector supports all GUID / UUID versions: v1, v2, v3, v4, v5, v6, v7 and v8.
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Result
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What is a GUID / UUID?
A GUID (Globally Unique Identifier) also called a UUID (Universally Unique Identifier), is a 128-bit identifier standardized by RFC 4122 and RFC 9562. It is designed to be globally unique, meaning no two GUIDs / UUIDs are expected to ever collide. Even when generated on different machines or at large scale.
GUIDs / UUIDs are widely used in databases, APIs, cloud services, distributed systems and software applications where reliable unique identifiers are essential. Their extremely low collision probability allows developers to create unique IDs without relying on a central authority or database lookup. Making them ideal for fast and scalable applications.
Universally Unique IDentifier (UUID) / Globally Unique IDentifier (GUID) - Wikipedia
GUID - Microsoft.com
RFC 4122 - ietf.org
RFC 9562 - ietf.org
Comparison of UUID / GUID Versions
| Version | Type | Deterministic? | Sortable? | Secure? | Typical Use | Standardized | Notes |
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| v1 | Time + Node (historically MAC) | No | Yes | MAC leak (historically) | Distributed systems | RFC 4122
(July 2005) | Includes timestamp + Node (historically the MAC address). Ordered but exposes hardware info. |
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| v2 | DCE Security (UID/GID) | No | Partial | Leaks IDs | Legacy DCE systems | RFC 4122
(July 2005) | Embeds POSIX UID/GID + MAC address. Rarely supported and considered obsolete. |
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| v3 | Name (MD5) | Yes | No | MD5 | Namespace-based IDs | RFC 4122
(July 2005) | Deterministic, but MD5 is cryptographically broken. |
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| v4 | Random | No | No | Yes | General purpose (Recommended) | RFC 4122
(July 2005) | Pure randomness (122 random bits). Extremely low collision probability. |
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| v5 | Name (SHA-1) | Yes | No | SHA-1 | Stable API IDs | RFC 4122
(July 2005) | Deterministic like v3 but uses SHA-1, which is no longer fully secure. |
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| v6 | Ordered time v1 | No | Yes | Yes | Database indexing | RFC 9562
(May 2024) | Improved v1 format with sortable structure + privacy-safe design. |
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| v7 | Timestamp + randomness | No | Yes | Yes | Latest most modern | RFC 9562
(May 2024) | Combines millisecond timestamps with strong randomness. Ideal for distributed systems. |
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| v8 | Custom / User-defined | Depends | Depends | Custom | Experimental, app-specific | RFC 9562
(May 2024) | Flexible GUID / UUID layout reserved for application-defined use. Not recommended for generic scenarios. |
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| empty-nil | Empty / Nil (all zeros) | Yes | N/A | No (not unique) | Sentinel / “no value” / placeholder | RFC 4122
RFC 9562 | Not a real identifier, used to represent “no value”. Never generate or use it for uniqueness. |
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Disclaimer: All information is provided for general educational and technical reference only. While we aim to keep the content accurate, current and aligned with published standards. No guarantees are made regarding completeness, correctness or suitability for any specific use case.
GUID / UUID specifications, RFCs, best practices, security guidance, database behavior and ecosystem conventions (including cloud platforms and third-party identifier formats) may change over time or differ by implementation. Examples, recommendations, and comparisons are illustrative and may not apply universally.
This content should not be considered legal, security, compliance or architectural advice. Before making critical design, security, or production decisions, always consult the latest official standards and documentation (such as RFC 4122, RFC 9562 and vendor-specific references).
Always evaluate behavior in your own environment.