UUID / GUID Validator & Inspector
Validate, analyze, and deconstruct UUIDs and GUIDs adhering to RFC 4122 and RFC 9562. Decode UUIDv7/v1 timestamps, inspect 128-bit binary fields, and validate batch lists with 100% client-side privacy.
Embedded Timestamp & Metadata (Unix Epoch (RFC 9562))
Normalized Representation Formats (1-Click Copy)
018d9f42-8f21-7b4e-a391-e2b4c8a1f930018d9f428f217b4ea391e2b4c8a1f930{018d9f42-8f21-7b4e-a391-e2b4c8a1f930}urn:uuid:018d9f42-8f21-7b4e-a391-e2b4c8a1f930128-Bit Binary & Hex Field Deconstruction (RFC 4122)
018d9f42Hex indices 0–78f21Hex indices 8–117b4eContains Version 7a391Contains Variant bitse2b4c8a1f930Hex indices 20–31 (Final 6 bytes)How UUID / GUID Validation Works (RFC 4122 & RFC 9562)
A Universally Unique Identifier (UUID) is a 128-bit numerical label represented as 32 hexadecimal digits displayed in 5 groups separated by hyphens (8-4-4-4-12):
The Version Nibble (M at index 14)
The high nibble of the 7th byte (represented by the 13th hex digit or character 14 in canonical representation) determines the generation algorithm:
- v1: Gregorian timestamp + IEEE 802 Node MAC address
- v4: 122 bits of pseudo-random entropy (CSPRNG)
- v7: 48-bit Unix epoch millisecond timestamp + 74 bits random (RFC 9562)
- Nil: All 128 bits zero (00000000-0000-0000-0000-000000000000)
- Max: All 128 bits one (ffffffff-ffff-ffff-ffff-ffffffffffff)
The Variant Bits (N at index 19)
The high bits of byte 8 (character 19) determine the layout specification:
- Hex 8, 9, a, b (10xx): Standard RFC 4122 / RFC 9562 (IETF Leach-Salz)
- Hex 0–7 (0xxx): Apollo Network Computing System (NCS) backward compatible
- Hex c, d (110x): Microsoft Corporation GUID (COM/OLE early architecture)
- Hex e, f (111x): Reserved for future standardization
Frequently Asked Questions
A valid Universally Unique Identifier (UUID) contains exactly 128 bits represented as 32 hexadecimal digits. In canonical representation, it is displayed in five hyphen-separated groups (8-4-4-4-12, such as 'f47ac10b-58cc-4372-a567-0e02b2c3d479'). Our validator accepts standard 36-character hyphenated strings, compact 32-character strings without hyphens, Microsoft C# braced GUIDs ({...}), and official URN formats (urn:uuid:...). It verifies that exactly 32 hexadecimal characters are present and that hyphens adhere to standard boundaries.
Under RFC 4122 and the modern RFC 9562 standards, the UUID Version is encoded in the 13th hexadecimal character (index 12 of clean hex or character 14 in canonical representation), ranging from 1 to 8, with special identifiers for Nil (all zeros) and Max (all ones). The Variant is encoded in the high bits of byte 8 (the 17th hexadecimal character or index 16 of clean hex). Our inspector tests the binary masks to identify standard IETF (RFC 4122 / RFC 9562 Leach-Salz), legacy Apollo NCS, Microsoft COM/OLE GUIDs, or reserved bit allocations.
For UUIDv7, the most significant 48 bits (the first 12 hex characters) encode unsigned Unix epoch milliseconds since January 1, 1970 UTC. Our decoder parses these 48 bits directly to derive UTC and ISO 8601 timestamps. For legacy UUIDv1, the 60-bit timestamp represents 100-nanosecond intervals since the Gregorian calendar reform (October 15, 1582 UTC). Our engine reassembles time_hi, time_mid, and time_low, subtracts the 122,192,928,000,000,000 100ns offset, and converts the remainder into Unix epoch milliseconds and human-readable UTC dates.
UUIDv4 allocates 122 bits to cryptographically secure pseudo-random numbers (CSPRNG), making it entirely opaque and non-sortable. In contrast, UUIDv7 (ratified in RFC 9562 in May 2024) embeds a 48-bit millisecond timestamp followed by 74 bits of random entropy. Because the timestamp resides in the most significant bits, UUIDv7 identifiers sort chronologically, preventing B-tree index fragmentation and page splits in high-throughput PostgreSQL, MySQL, and MongoDB databases.
A Nil UUID (00000000-0000-0000-0000-000000000000) is a special all-zero identifier specified in RFC 4122 Section 4.1.7 used to represent an empty, uninitialized, or null database foreign key. A Max UUID (ffffffff-ffff-ffff-ffff-ffffffffffff) is defined in RFC 9562 Section 5.9 as an all-ones identifier commonly used as an upper sentinel boundary in distributed range queries and range partitioning.
100% private. All validation algorithms, format normalizers, bitwise field decompositions, timestamp decoding, and batch processing execute exclusively in your local browser volatile memory via client-side JavaScript. Zero UUIDs, database keys, session tokens, or customer identifiers are ever transmitted to any external server or analytics service.