# Snowflake vs UUID vs UUIDv7(2023)

Property

Snowflake

UUID v4

UUIDv7

Size

64-bit int

128-bit

128-bit

Format

Integer (e.g. 1541815603606036480)

Hex string (e.g. 550e8400-e29b-...)

Hex string (e.g. 018e-...)

Time-sortable

✅ Yes (ms precision)

❌ No

✅ Yes (ms precision)

Globally unique

⚠️ Within a coordinated cluster

✅ Yes (~2¹²² entropy)

✅ Yes (~74 bits entropy)

Requires coordination

✅ Yes (machine ID assignment)

❌ No

❌ No

DB index performance

✅ Excellent (sequential)

❌ Poor (random, index fragmentation)

✅ Excellent (sequential)

Embeds timestamp

✅ Yes

❌ No

✅ Yes

Human extractable time

✅ Yes

❌ No

✅ Yes

Collision risk

Very low (coordinated)

Negligible (random)

Very low

Standard

Proprietary

RFC 4122

RFC 9562 (2023)

Cross-system portability

⚠️ Epoch is custom

✅ Universal

✅ Universal