Developer Tools for Random Data Generation // v2.13.1
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Random UUID v7 Generator

Generate modern UUID version 7 identifiers with Unix timestamp prefix - combining chronological sortability with random uniqueness for optimal database performance

Our UUID v7 generator creates time-ordered universally unique identifiers using Unix timestamps with millisecond precision per the latest RFC 9562 standard (2024). Generate UUID version 7 with timestamp-based sortability and cryptographic randomness for optimal database indexing, distributed systems, and time-series data. Perfect for modern applications requiring sortable unique identifiers without MAC address exposure - the recommended UUID format for new projects combining best features of v1 (sortability) and v4 (privacy, randomness).

What is UUID v7?

UUID v7 (Universally Unique Identifier version 7) is the newest time-ordered identifier format defined in RFC 9562 (approved 2024), designed to address limitations of earlier UUID versions. It combines a 48-bit Unix timestamp (millisecond precision since Unix epoch 1970-01-01) with 74 bits of cryptographic randomness, creating identifiers that are both chronologically sortable and globally unique. Unlike v1 (which exposes MAC addresses) and v4 (which lacks sortability), v7 provides the best of both worlds: privacy-friendly random generation with natural time-based ordering that significantly improves database index performance and query efficiency.

The format follows the standard 32 hexadecimal digits in 5 groups: 8-4-4-4-12 (e.g., 01850c1e-7e9a-7b2c-8f3a-6b4d2e1c9a8b). The timestamp prefix ensures UUIDs sort chronologically, making v7 ideal for time-series databases, event logs, distributed systems, and any application where creation time ordering matters. The random suffix provides collision resistance comparable to v4 while the timestamp prefix eliminates database index fragmentation issues caused by purely random UUIDs. UUID v7 is rapidly becoming the recommended choice for new projects, offering modern design, excellent database performance, privacy protection, and standardized timestamp semantics for distributed architectures.

UUID v7 Generator Configuration

Quantity (1-100 UUIDs)

Generate multiple UUID v7 identifiers simultaneously. Each UUID includes precise Unix timestamp (millisecond) plus cryptographic random bits, ensuring chronological ordering even when generated in rapid succession within the same millisecond.

Timestamp-Based Sortability

UUIDs sort chronologically by creation time thanks to the 48-bit Unix timestamp prefix. This dramatically improves database B-tree index performance, reduces fragmentation, and enables efficient time-range queries without additional timestamp columns.

Cryptographic Randomness

The 74-bit random suffix uses CSPRNG ensuring unpredictability and collision resistance comparable to UUID v4. Provides privacy protection by avoiding MAC addresses while maintaining astronomical uniqueness probability across distributed systems.

Export Formats

Export generated UUIDs as plain text (TXT), comma-separated values (CSV), or JSON with embedded timestamp metadata for integration into time-series databases, distributed ledgers, event sourcing systems, and modern cloud applications.

How to Generate UUID v7

[STEP 1] Set Quantity

Choose how many UUID v7 identifiers to generate (1-100). Each UUID includes a Unix timestamp prefix, ensuring chronological ordering even when generated milliseconds apart or within the same millisecond.

[STEP 2] Generate Instantly

Click EXECUTE GENERATION to create time-ordered UUIDs. Each identifier embeds the current Unix timestamp (millisecond precision) plus cryptographic random bits for uniqueness and collision resistance. No configuration needed - v7 automatically includes timestamp.

[STEP 3] Copy & Use

Click individual UUIDs to copy them instantly, or use export buttons to download all UUIDs as TXT, CSV, or JSON with timestamp metadata for database insertion, event sourcing, distributed systems, or time-series applications.

[STEP 4] Leverage Sortability

Use UUID v7 for database primary keys (chronologically ordered), event IDs (naturally sorted by time), distributed logs (time-ordered across servers), audit trails, transaction IDs, or any application benefiting from time-based sortability with random uniqueness.

UUID v7 Best Practices

  • _ Modern Default Choice - UUID v7 is the recommended UUID version for new projects starting in 2024+. It combines the best features of v1 (sortability) and v4 (privacy, randomness) without their drawbacks.
  • _ Database Performance - Leverage v7's timestamp prefix for superior database index performance. Chronological ordering reduces B-tree fragmentation and improves INSERT performance compared to random v4 UUIDs.
  • _ Time-Series Data - Ideal for event logs, audit trails, transaction histories, and distributed ledgers where natural time-based ordering eliminates the need for separate created_at timestamp indexes.
  • _ Distributed Systems - Use v7 in microservices, distributed databases, and multi-region deployments where servers independently generate IDs that naturally merge-sort by creation time without coordination.
  • _ Migration from v1 - Replace UUID v1 with v7 to maintain sortability while eliminating MAC address privacy concerns. v7 provides better database performance and modern timestamp semantics.
  • _ Clock Synchronization - While v7 tolerates clock skew better than v1, ensure reasonable NTP synchronization across distributed nodes for optimal chronological ordering across systems.

Technical Implementation

UUID v7 follows RFC 9562 specification (2024), combining Unix timestamp prefix with cryptographic random suffix for time-ordered unique identifiers:

// UUID v7 Structure (128 bits total)
Algorithm: Time-Ordered UUID with Unix Timestamp

// Step 1: Get Unix timestamp (milliseconds)
unix_ts_ms = milliseconds since 1970-01-01 00:00:00 UTC

// Step 2: Generate random bits
random_a = CSPRNG(12 bits)
random_b = CSPRNG(62 bits)

// Structure Layout:
unix_ts_ms (48 bits) - Millisecond timestamp
ver (4 bits) - Version = 7 (0111)
rand_a (12 bits) - Random subsecond precision
var (2 bits) - Variant = 10 (RFC 9562)
rand_b (62 bits) - Random uniqueness

// Total Random Bits: 74 bits (rand_a + rand_b)
Collision Resistance: 2^74 per millisecond

// Format: xxxxxxxx-xxxx-7xxx-yxxx-xxxxxxxxxxxx
// First 48 bits = timestamp (sortable)
Example: 01850c1e-7e9a-7b2c-8f3a-6b4d2e1c9a8b

Timestamp Range: 1970 to 10889 AD (8000+ years)

API Access for Developers

Generate UUID v7 identifiers programmatically using our free REST API. Includes Unix timestamp prefix for chronological sortability.
GET https://generate-random.org/api/v1/generate/uuids?version=7&count=10
VIEW FULL API DOCUMENTATION

Frequently Asked Questions

Why should I use UUID v7 instead of v4?
UUID v7 offers significant advantages for database-heavy applications: chronological sortability improves index performance, reduces fragmentation, and enables efficient time-range queries. Use v7 for time-series data, event logs, audit trails, and distributed systems where creation time matters. Use v4 for maximum compatibility with existing systems, when time-ordering is irrelevant, or for API tokens where randomness is paramount. For new projects started in 2024+, v7 is generally the better choice.
How does UUID v7 compare to v1?
Both are time-ordered, but v7 is superior: (1) Unix timestamp prefix (milliseconds) vs v1's Gregorian timestamp (100-nanosecond intervals), (2) No MAC address exposure - v7 uses random bits for privacy, (3) Better database index performance due to timestamp prefix location, (4) Modern RFC 9562 standard (2024) vs legacy RFC 4122 (2005), (5) Natural lexicographic sorting matches chronological order. Use v7 for new projects; v1 only for legacy compatibility.
Are UUID v7 identifiers truly sortable?
Yes! UUID v7 sorts chronologically because the first 48 bits are a Unix timestamp (milliseconds since 1970). UUIDs generated later have higher timestamp values and sort after earlier ones. This provides natural time-ordering for database indexes, efficient time-range queries (WHERE id BETWEEN min AND max), and chronological merging in distributed systems. Within the same millisecond, random bits provide deterministic ordering but chronological meaning only applies across different milliseconds.
Can UUID v7 have collisions?
Collision probability is extremely low. With 74 random bits, there are 2^74 ≈ 18.9 quadrillion possible UUIDs per millisecond. Even generating a million UUIDs per millisecond, collision probability remains negligible. Across distributed systems with reasonable clock synchronization, v7 provides collision resistance comparable to v4 while adding chronological sortability. Always use database unique constraints as defense-in-depth.
Is UUID v7 widely supported yet?
UUID v7 support is growing rapidly after RFC 9562 approval in May 2024. Major languages have libraries: JavaScript (uuid v10+), Python (uuid6-python), Go (google/uuid v1.6+), Java (uuid-creator), Rust (uuid v1.7+). Database support: PostgreSQL 17+ (gen_random_uuid_v7), modern ORMs are adding support. While not yet universal like v4, v7 is rapidly becoming the recommended choice for new projects. The RFC is standardized and implementation is straightforward.