UUID Decoder & Inspector — Decode Timestamp & All Fields
Generate v1, v3, v4, v5, v6, v7 UUIDs · Bulk export · Validate · Inspect · Batch check
Paste any UUID to decode all its internal fields — version, variant, embedded timestamp (v1/v6/v7), node address (v1), clock sequence, and more. UUID v1 and v6 timestamps are decoded from Gregorian epoch to human-readable date. UUID v7 Unix millisecond timestamp is decoded to ISO 8601 datetime.
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Frequently Asked Questions
How does the UUID Inspector decode v1 timestamps?
UUID v1 stores a 60-bit timestamp counting 100-nanosecond intervals since October 15, 1582 (Gregorian calendar epoch). The inspector extracts the three timestamp fields (time_low, time_mid, time_hi), reconstructs the 60-bit value, subtracts the 12219292800000ms offset between 1582 and 1970, and converts to a human-readable ISO 8601 UTC datetime.
Can I find the MAC address from a v1 UUID?
UUID v1 includes a 48-bit "node" field in the last 12 hex characters. This was originally intended to store the generating host's MAC address, though modern implementations often use a random node for privacy. The UUID Inspector displays the node value, but it may be random rather than a real MAC address depending on the generating library.
What fields does the UUID Inspector show?
The inspector decodes: Raw UUID, Hex (no hyphens), Version, RFC 4122 Variant, embedded Timestamp (for v1/v6/v7 — decoded to human date), Clock Sequence (v1/v6), Node address (v1/v6), Hash algorithm (v3/v5), Uppercase format, URN format, Braces format, and Short ID (first 8 chars with collision warning).
How does UUID v7 timestamp decoding work?
UUID v7 stores a 48-bit Unix millisecond timestamp in the first 12 hex characters (first two groups). The inspector reads these 12 hex digits, parses them as a base-16 integer to get milliseconds since Unix epoch (January 1, 1970), then converts to an ISO 8601 datetime. This is far simpler than v1's Gregorian epoch calculation.
What is the clock sequence in a UUID v1?
The 14-bit clock sequence (bits 16–17 of the 9th byte encode the variant, remaining 14 bits are the sequence) prevents duplicate UUIDs when the clock is set back or the node changes. It is randomised on UUID library initialisation and incremented on each generation within the same millisecond. The inspector shows it as a 4-digit hex value.
Can I inspect a UUID from a JWT or database record?
Yes — paste any UUID format (standard hyphenated, no-hyphens, braces, or URN) into the Inspect tab. The tool auto-detects and normalises the format before decoding. This is useful for debugging database records, tracing distributed system logs by timestamp, or understanding UUIDs embedded in JWT sub claims.