UUIDv7 doesn't have the properties you think it does
When timestamps aren’t time-ordered and other oddities
Quick read
This blog post analyses UUIDv7 and argues it does not reliably provide monotonic ordering or accurate creation timestamps under the RFC and many implementations. It explains how RFC allowances and implementation behaviors can make embedded timestamps incorrect, non-monotonic, or advance arbitrarily ahead of system time, so you should not rely on UUIDv7 for strict ordering or precise creation times
- UUIDv7 guarantees uniqueness but not strict monotonic order
- Implementations may alter or advance the embedded timestamp
- Donu2019t trust UUIDv7 as an authoritative creation-time source
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A closer look at UUIDv7 doesn't have the properties you think it does
Author's take: UUIDv7 is weird
This is a blog post arguing that UUIDv7 does not reliably provide some commonly touted benefits. The author says the only strictly guaranteed property of UUIDv7 is uniqueness (collision resistance). They call out that UUIDv7 can be u201cweirdu201d because other expected properties are not strictly held by the RFC or many implementations.
What the site demonstrates you can actually do
The post walks through specific behaviors and pitfalls: the embedded timestamp may not equal the object creation time, implementations are allowed by RFC 9562 to alter or increment the timestamp, and some implementations (the author cites Pythonu2019s uuid.uuid7()) can increment the timestamp and even get into runaway states when the clock jumps backwards. It also explains that many implementations do not persist the last used timestamp across restarts.
Who should read this and why it matters
Developers and engineers who considered using UUIDv7 for ordering, auditing, or leaking-sensitive-timestamp concerns will find the post useful. The author explains that UUIDv7 can leak a high-precision timestamp in an ID (for example in URLs) and that UUIDv7u2019s ordering guarantees are at best u201croughu201d because clocks and counters introduce uncertainty. The post encourages caution: UUIDv7 can be useful for roughly ordered IDs, but you should not assume strict monotonicity or exact timestamps.
Questions people ask about UUIDv7 doesn't have the properties you think it does
- Does the post claim UUIDv7 is unique?
- Yes - the author states the only useful property UUIDv7 appears to strictly provide is uniqueness (collision resistance).
- Will UUIDv7 timestamps always match creation time?
- No - the post cites RFC text and implementations showing the embedded timestamp may not equal the time the UUID was generated and implementations may alter the timestamp.
- Should I rely on UUIDv7 for strict ordering of events?
- No - the author explains timestamps are only time-ordered if clocks are precise and synchronized; UUIDv7 cannot guarantee strict monotonic ordering and is at best roughly ordered.
UUIDv7 doesn't have the properties you think it does was shared on NexURLs by Nexis on October 24, 2026, in Learning & Books.
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Quick answers
What is UUIDv7 doesn't have the properties you think it does?
UUIDv7 doesn't have the properties you think it does (alexsci.com): This blog post analyses UUIDv7 and argues it does not reliably provide monotonic ordering or accurate creation timestamps under the RFC and many implementations. It explains how RFC allowances and implementation behaviors can make embedded timestamps incorrect, non-monotonic, or advance...
Who shared UUIDv7 doesn't have the properties you think it does on NexURLs?
It was shared by Nexis in October 2026. Every link on NexURLs is shared by a real member and passes a safety check before it goes out.
What are some sites like UUIDv7 doesn't have the properties you think it does?
Members found these close to it: Consistency is not a localized property, Postgres 15 improves UNIQUE and NULL, Privnote. The full list is on this page under Sites like UUIDv7 doesn't have the properties you think it does.
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