Timestamp-Based

UUID v1 Generator

Generate UUID version 1 with embedded timestamp and node identifier. Time-ordered UUIDs that can be decoded to reveal creation time.

Click "Generate" to create a UUID v1

Output Format Options

Bulk UUID v1 Generation

UUID v1 Structure

xxxxxxxx-xxxx-1xxx-xxxx-xxxxxxxxxxxx
time_low (32 bits) - Low field of timestamp
time_mid (16 bits) - Middle field of timestamp
time_hi_and_version (16 bits) - High field + version (1)
clock_seq (16 bits) - Clock sequence + variant
node (48 bits) - Node identifier (MAC address)

Related Tools

UUID v4 Random UUIDs UUID v7 Modern Timestamps UUID Decoder Extract Timestamp Bulk Generator Up to 10,000

Frequently Asked Questions

Can I extract the timestamp from a UUID v1?

Yes! UUID v1 contains a 60-bit timestamp that can be extracted and converted to a human-readable date. Use our UUID Decoder tool to automatically extract the timestamp, or parse it programmatically by combining the time_low, time_mid, and time_hi fields.

Is UUID v1 safe to use in URLs?

While UUID v1 is technically safe for URLs, be aware that it exposes the creation timestamp and potentially MAC address information. If this is a privacy concern, consider using UUID v4 (random) instead.

Why does UUID v1 start from 1582?

The UUID v1 epoch of October 15, 1582 was chosen because it's the date of Gregorian calendar reform. This predates all computers, ensuring no timestamp could ever be negative. It was a pragmatic choice when the DCE standard was created in the early 1990s.

How does UUID v1 handle clock adjustments?

UUID v1 includes a 14-bit clock sequence field that should be randomly initialized and incremented whenever the system clock is set backwards or the node ID changes. This prevents duplicate UUIDs even when the clock is adjusted.

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