Community Notes — Do They Work Against Disinformation?

In March 2025, Meta launched its “Community Notes” in the United States, a feature that allows selected users to add context to posts that might be misleading on Facebook, Instagram and Threads. This system, used by Twitter (now X) since 2021, places the responsibility of flagging mistakes or inaccuracies in posts to selected users, thus replacing professional fact-checkers. The evidence available on the effectiveness of this kind of program comes mainly from X’s experience since Meta has not made data available for researchers.

For a more in-depth and detailed analysis about all the evidence available, see “Community Notes — Evidence of Their Effectiveness Against Disinformation.”

How Do They Work?

---

To write notes, users have to sign up, meet certain criteria and not have violated the platform’s policies. Every note must include at least one link to a source that supports it. Once the note is submitted, other contributors rate it, and it only gets published if enough contributors agree that the note is helpful. But here is the key point: for a note to be posted and made visible to everybody, it is not enough for the majority to approve it. It must reach consensus among users who normally disagree with each other. The reasoning is that if people who don’t usually agree with each other consider that a note is helpful, it probably is for everybody.

What is the Quality of the Notes?

---

Several studies have assessed the quality of these notes by analyzing the sources they quoted to support their arguments. One study that examined over 500,000 notes on X found that, among the top quoted sources, there were renowned media outlets like CNN, Reuters and BBC, institutions such as WHO, and fact-checking organizations. In another study, that analyzed over a million proposed notes in 2024, it was observed that around 3.7% included links to certified fact-checkers, making them the third most quoted source globally. In addition, another study on COVID-19 vaccination notes showed that 97% of them were supported by robust scientific evidence.

However, the system has vulnerabilities. Because it is collaborative, it can be manipulated — some users give poor ratings to reliable sources to prevent certain corrections from being posted.

The Issue with Consensus

---

Although the requirement of reaching consensus among users to make a note visible sounds reasonable, it works as a barrier. A study about the 2024 U.S. elections showed that 74% of the notes were never published, although many were accurate and quoted quality sources. As a result, posts with incorrect information had over 2.2 billion views without their corresponding correction. Another study that examined over 1.7 million notes posted between 2021 and 2025 observed that only 7.1% of all submissions in English and 4.7% in Spanish are posted. Another study showed that nine out of ten corrections are never shown. 

Do They Reduce Virality?

---

A study published in 2025 analyzed over 40,000 X posts and found that when a note reaches the required consensus and becomes visible, that tweet has fewer shares, spreads less and loses traction. Notes not only slow down the initial spread; they also modify the way in which content circulates, affecting especially the chain-based spread among users. 

The analysis also identified that speed is key: the quicker the note gets posted, the less viral it gets. Notes that appear late have almost no effect. Additionally, other studies found that the time between the publication of the tweet and the publication of the accompanying note — which provides context — is still too long and does not keep pace with the speed at which misinformation is produced and disseminated on the platform.

Do They Replace Fact-Checkers?

---

Evidence shows that they do not. Notes supported by professional fact-checks are 12% more likely to be published. They also appear more quickly. This suggests that Community Notes do not replace fact-checkers, they complement them. Fact-checkers conduct in-depth verifications that regular users cannot do, while Notes help to spread that work.

In summary, although Community Notes can reduce the virality of false content when published, certain features of the system significantly limit their effectiveness against disinformation. Evidence shows that the contribution of professional fact-checkers is crucial to improving the performance of this collaborative system.