TF
TruthOrFake
Fact Check: Are UUIDs unique across systems?

Fact Check: Are UUIDs unique across systems?

Published May 7, 2025
ByFactChecker 1.1 avatarFactChecker 1.1
±
VERDICT
Partially True

# Are UUIDs Unique Across Systems? The claim that "UUIDs are unique across systems" raises questions about the reliability and effectiveness of Unive...

Are UUIDs Unique Across Systems?

The claim that "UUIDs are unique across systems" raises questions about the reliability and effectiveness of Universally Unique Identifiers (UUIDs) in various computing environments. UUIDs are designed to be unique identifiers that can be generated independently across different systems without requiring a central authority. However, the extent to which they achieve this uniqueness is subject to scrutiny, particularly concerning the methods used for their generation and the potential for collisions.

What We Know

  1. Definition and Purpose: UUIDs are 128-bit identifiers standardized in RFC 4122, intended to provide a means of uniquely identifying information across distributed systems without central coordination 24. They were originally developed for the Apollo Network Computing System in the 1980s 3.

  2. Generation Methods: There are different versions of UUIDs, each employing various algorithms for generation. For example, UUID version 1 uses a combination of the current timestamp and the MAC address of the generating machine, while version 4 generates UUIDs based on random numbers. The uniqueness of a UUID can depend significantly on the method used for its generation 56.

  3. Collision Probability: The likelihood of UUID collisions—instances where two UUIDs are the same—varies based on the entropy of the generation method. For instance, UUIDs generated using a timestamp and MAC address may have lower entropy compared to those generated purely from random bits, leading to a higher risk of collisions 5.

  4. Practical Use Cases: UUIDs are widely used in various applications, including databases and distributed systems, where unique identification is crucial. They facilitate data integrity and interoperability across different platforms 610.

  5. Standards and Compliance: UUIDs adhere to formal standards that aim to ensure their uniqueness. However, the implementation of these standards can vary across different programming languages and systems, which may affect their reliability in practice 48.

Analysis

Source Evaluation

  • Academic and Technical Sources: The study by Sinha 1 provides a detailed examination of UUID standards and their implications for data integrity. However, as it is a self-published PDF, its peer-review status and the author's potential bias (being a software engineer at Walmart) should be considered when evaluating its credibility.

  • Wikipedia: The Wikipedia entry on UUIDs 2 is a generally reliable source, as it is frequently updated and cites multiple references. However, it may lack depth in technical details and can be edited by anyone, which raises questions about the accuracy of specific claims.

  • Blog Posts and Articles: Sources like the blog from PingCAP 6 and the article from SDE Tools 7 provide useful insights into the practical applications of UUIDs. However, they may reflect the authors' perspectives and biases, particularly if they are promoting specific technologies or methodologies.

  • Stack Overflow: The discussion on Stack Overflow 5 highlights practical concerns about UUID generation and collision risks. While it offers valuable community insights, the information is anecdotal and should be corroborated with more authoritative sources.

Conflicting Information

While many sources assert that UUIDs are designed to be unique across systems, they also acknowledge the conditions under which this uniqueness can be compromised. For instance, the potential for collisions due to low entropy in certain UUID generation methods is a critical point that contradicts the absolute claim of uniqueness.

Additional Context

Understanding the technical specifications and practical implementations of UUIDs is essential for evaluating their reliability. Further research could include empirical studies measuring collision rates in various UUID generation methods or case studies from organizations that have implemented UUIDs at scale.

Conclusion

Verdict: Partially True

The assertion that UUIDs are unique across systems is partially true. While UUIDs are designed to be unique identifiers, their actual uniqueness can be influenced by the method of generation and the conditions under which they are created. For example, UUIDs generated using low-entropy methods may have a higher risk of collisions, which undermines the claim of universal uniqueness.

It is important to note that while UUIDs adhere to formal standards aimed at ensuring their uniqueness, variations in implementation across different systems and programming languages can affect their reliability. This complexity introduces a level of uncertainty regarding their absolute uniqueness.

Readers should be aware of these nuances and critically evaluate the information surrounding UUIDs, especially when considering their use in applications requiring guaranteed uniqueness. Further empirical research could provide more definitive insights into the collision rates and effectiveness of different UUID generation methods.

Sources

  1. Sinha, A. R. (2023). Beyond Randomness: A Detailed Study on UUID Standards, Data Integrity, and Identifier Design Across Storage Systems. Link

  2. Universally unique identifier - Wikipedia. Link

  3. UUIDs Explained: Your Ultimate Handbook to Understanding Unique Identifiers. Link

  4. Complete guide to Universal Unique Identifiers (UUID) - UUIDTools.com. Link

  5. Are UUIDs unique across different systems? - Stack Overflow. Link

  6. The Benefits of Using UUIDs for Unique Identification - PingCAP. Link

  7. Understanding UUIDs: A Deep Dive into Unique Identifiers. Link

  8. PDF RFC 9562: Universally Unique IDentifiers (UUIDs). Link

  9. Understanding UUID: Purpose and Benefits of a Universal Unique Identifier. Link

  10. How Unique Identifiers (UUIDs) Minimize Risk & Enhance Data Security. Link

Have a claim you want to verify? It's 100% Free!

Our AI-powered fact-checker analyzes claims against thousands of reliable sources and provides evidence-based verdicts in seconds. Completely free with no registration required.

💡 Try:
"Coffee helps you live longer"
✓100% Free
✓No Registration
✓Instant Results

Comments

Leave a comment

Loading comments...

More Fact Checks to Explore

Discover similar claims and stay informed with these related fact-checks

Fact Check: Are UUIDs guaranteed to be unique?
Partially True
🎯 Similar

Fact Check: Are UUIDs guaranteed to be unique?

Detailed fact-check analysis of: Are UUIDs guaranteed to be unique?

May 7, 2025
Read more →
Fact Check: Transcript 00:00 911 was a false flag. For the first 10 years, I did not think anything other than the official narrative then after being shown a video, a close up video of building number seven coming down and that got me going because it's obvious to me that building seven was was a controlled demolition because the building collapses from the bottom down. The trade centers were unique in that they were designed to withstand the 00:33 impact of a a a jet. From what I understand the the outer skeleton of the building. The outer columns was like a a fish net and you had these inner core columns which was substantial thick steel beams to withstand four or five times what the loads were. Got it. The engineers always over design a building. No steel frame building has ever collapsed before or since 9/ eleven. So that should say something right there. And it said that building seven it was 01:05 aggressive collapse that it was caused by fire but progressive collapse unlike the twin towers, the twin towers collapse from the top down. That's a progressive collapse. Sure. Floor by floor by floor. But if you look at the videos of building seven collapsing, it collapses uniformly, it's collapsing from the bottom, the building stays intact all the way to the bottom of the ground and you could see the sides caving in on it. For a building to collapse uniformly which the video show all the load bearing it would have to have failed 01:36 simultaneously. Now, fire doesn't act like that. I came across an analogy of the twin towers and if you could visualize cast iron stoves stacked. One on top of each other. The stoves up at the top. Yes, there's fire and they've been damaged but the stoves on the bottom, they haven't been damaged. Okay. So, the structure underneath all of that is intact. So, it's impossible for a building to collapse near free fall speed and increase. Without a 02:07 controlled demolition. You're running into the path of most resistance. I something else is going on. I don't believe that it was just the planes or the fires I think that and they examine the dust and they found what they call thermitic material which is like a explosive incendiary which was in the dust samples and that's documented. There were reports of the buildings were undergoing a extensive elevator renovation in the two or three years prior to all kinds of 02:40 workers they had access to the the core the cores of the building and on the day of the attack the the elevator company would not assist in the operations of the elevators and the elevator company was the elevator company it subsequently went out of business and a couple of years after that
False
🎯 Similar

Fact Check: Transcript 00:00 911 was a false flag. For the first 10 years, I did not think anything other than the official narrative then after being shown a video, a close up video of building number seven coming down and that got me going because it's obvious to me that building seven was was a controlled demolition because the building collapses from the bottom down. The trade centers were unique in that they were designed to withstand the 00:33 impact of a a a jet. From what I understand the the outer skeleton of the building. The outer columns was like a a fish net and you had these inner core columns which was substantial thick steel beams to withstand four or five times what the loads were. Got it. The engineers always over design a building. No steel frame building has ever collapsed before or since 9/ eleven. So that should say something right there. And it said that building seven it was 01:05 aggressive collapse that it was caused by fire but progressive collapse unlike the twin towers, the twin towers collapse from the top down. That's a progressive collapse. Sure. Floor by floor by floor. But if you look at the videos of building seven collapsing, it collapses uniformly, it's collapsing from the bottom, the building stays intact all the way to the bottom of the ground and you could see the sides caving in on it. For a building to collapse uniformly which the video show all the load bearing it would have to have failed 01:36 simultaneously. Now, fire doesn't act like that. I came across an analogy of the twin towers and if you could visualize cast iron stoves stacked. One on top of each other. The stoves up at the top. Yes, there's fire and they've been damaged but the stoves on the bottom, they haven't been damaged. Okay. So, the structure underneath all of that is intact. So, it's impossible for a building to collapse near free fall speed and increase. Without a 02:07 controlled demolition. You're running into the path of most resistance. I something else is going on. I don't believe that it was just the planes or the fires I think that and they examine the dust and they found what they call thermitic material which is like a explosive incendiary which was in the dust samples and that's documented. There were reports of the buildings were undergoing a extensive elevator renovation in the two or three years prior to all kinds of 02:40 workers they had access to the the core the cores of the building and on the day of the attack the the elevator company would not assist in the operations of the elevators and the elevator company was the elevator company it subsequently went out of business and a couple of years after that

Detailed fact-check analysis of: Transcript 00:00 911 was a false flag. For the first 10 years, I did not think anything other than the official narrative then after being shown a video, a close up video of building number seven coming down and that got me going because it's obvious to me that building seven was was a controlled demolition because the building collapses from the bottom down. The trade centers were unique in that they were designed to withstand the 00:33 impact of a a a jet. From what I understand the the outer skeleton of the building. The outer columns was like a a fish net and you had these inner core columns which was substantial thick steel beams to withstand four or five times what the loads were. Got it. The engineers always over design a building. No steel frame building has ever collapsed before or since 9/ eleven. So that should say something right there. And it said that building seven it was 01:05 aggressive collapse that it was caused by fire but progressive collapse unlike the twin towers, the twin towers collapse from the top down. That's a progressive collapse. Sure. Floor by floor by floor. But if you look at the videos of building seven collapsing, it collapses uniformly, it's collapsing from the bottom, the building stays intact all the way to the bottom of the ground and you could see the sides caving in on it. For a building to collapse uniformly which the video show all the load bearing it would have to have failed 01:36 simultaneously. Now, fire doesn't act like that. I came across an analogy of the twin towers and if you could visualize cast iron stoves stacked. One on top of each other. The stoves up at the top. Yes, there's fire and they've been damaged but the stoves on the bottom, they haven't been damaged. Okay. So, the structure underneath all of that is intact. So, it's impossible for a building to collapse near free fall speed and increase. Without a 02:07 controlled demolition. You're running into the path of most resistance. I something else is going on. I don't believe that it was just the planes or the fires I think that and they examine the dust and they found what they call thermitic material which is like a explosive incendiary which was in the dust samples and that's documented. There were reports of the buildings were undergoing a extensive elevator renovation in the two or three years prior to all kinds of 02:40 workers they had access to the the core the cores of the building and on the day of the attack the the elevator company would not assist in the operations of the elevators and the elevator company was the elevator company it subsequently went out of business and a couple of years after that

Jul 28, 2025
Read more →
Fact Check: Are UUIDs unique?
Mostly True
🎯 Similar

Fact Check: Are UUIDs unique?

Detailed fact-check analysis of: Are UUIDs unique?

May 7, 2025
Read more →
Fact Check: Are UUIDs always unique?
Mostly False

Fact Check: Are UUIDs always unique?

Detailed fact-check analysis of: Are UUIDs always unique?

May 7, 2025
Read more →
Fact Check: Reality is a flux of endlessly changing phenomena. Concepts freeze this flux and present it as something fixed and stable. This distortion is a lie: we treat unequal things as if they were equal, thereby misrepresenting them. Nearly every word is a concept, and every concept is a simplification of a unique, unrepeatable experience. When we name something, we group many different and unequal experiences under a single term. This act of generalization ignores the actual differences between individual things and moments. Humans invent words generally based on their sensory experience. Those words become concepts, not exact representations. Over time, we forget the metaphorical origin and treat the word as “truth.” Words aren’t truths—just metaphors that have been socially stabilized. Words do not describe the world—they construct a simplified fiction of it, which we often mistakenly call “reality.”
Partially True

Fact Check: Reality is a flux of endlessly changing phenomena. Concepts freeze this flux and present it as something fixed and stable. This distortion is a lie: we treat unequal things as if they were equal, thereby misrepresenting them. Nearly every word is a concept, and every concept is a simplification of a unique, unrepeatable experience. When we name something, we group many different and unequal experiences under a single term. This act of generalization ignores the actual differences between individual things and moments. Humans invent words generally based on their sensory experience. Those words become concepts, not exact representations. Over time, we forget the metaphorical origin and treat the word as “truth.” Words aren’t truths—just metaphors that have been socially stabilized. Words do not describe the world—they construct a simplified fiction of it, which we often mistakenly call “reality.”

Detailed fact-check analysis of: Reality is a flux of endlessly changing phenomena. Concepts freeze this flux and present it as something fixed and stable. This distortion is a lie: we treat unequal things as if they were equal, thereby misrepresenting them. Nearly every word is a concept, and every concept is a simplification of a unique, unrepeatable experience. When we name something, we group many different and unequal experiences under a single term. This act of generalization ignores the actual differences between individual things and moments. Humans invent words generally based on their sensory experience. Those words become concepts, not exact representations. Over time, we forget the metaphorical origin and treat the word as “truth.” Words aren’t truths—just metaphors that have been socially stabilized. Words do not describe the world—they construct a simplified fiction of it, which we often mistakenly call “reality.”

Aug 5, 2025
Read more →
Fact Check: Are UUIDs sequential?
Partially True

Fact Check: Are UUIDs sequential?

Detailed fact-check analysis of: Are UUIDs sequential?

May 7, 2025
Read more →
Explore All Fact Checks
Fact Check: Are UUIDs unique across systems? | TruthOrFake Blog