Wikimedia Foundation brings legal challenge to new UK Online Safety Act requirements

On 8 May, 2025, the Wikimedia Foundation announced that it is challenging the lawfulness of a new element of the UK’s Online Safety Act (OSA) that determines what duties a website has under the law. This legal challenge is a last resort. It comes after years of sharing our concerns with UK policymakers that these measures — meant to improve online safety on major commercial platforms — could have detrimental consequences for public interest platforms like Wikipedia. These concerns remained unaddressed. We are taking action now to protect Wikipedia users, as well as the global accessibility and integrity of free knowledge.  

This blog post provides an overview of our legal challenge, what it means for Wikimedians around the world, and what might happen next. Read our Medium blog post for more information about the case.

What is the Online Safety Act and why does it matter for the Wikimedia movement?

The OSA was originally introduced to hold large commercial platforms accountable for the safety of the people who visited their websites. It came at a time when governments around the world were beginning to address critical concerns around harmful and abusive content. 

The UK was poised as one of the first governments to take concrete action on the topic. We therefore followed the developments closely, knowing that the UK’s approach could become a blueprint for legislation in other countries. 

From the start, the law’s focus on holding commercial platforms accountable meant that little attention was paid to how it might negatively impact public interest platforms like Wikipedia. As things stand, it threatens the very measures that we rely on to promote online safety, requiring that the Foundation interfere with users’ editing decisions and perhaps even verify their age. These concerns were shared alongside Wikimedia UK in meetings with the government, Parliamentary debates, prominent media outlets, and an open letter. These issues remain, even after stark warnings from the UK Parliament and civil society. 

It is important to reaffirm that the Foundation, and the Wikimedia movement as a whole, are deeply committed to advancing online safety. This is essential to our mission. A world in which everyone, everywhere, can share in the creation of free knowledge is only possible if everyone, everywhere, can contribute without fear for their safety. Our commitment to online safety is reflected in our transparency reports, privacy policy, and Universal Code of Conduct, among other measures. Yet under the OSA, our users’ ability to participate safely and freely in Wikimedia’s privacy-first, open, collaborative, model is at risk. 

What element of the law is the Wikimedia Foundation challenging? 

The Foundation is challenging the OSA’s Categorisation Regulations, which are written broadly enough that they could place Wikipedia as a “Category 1 service” — a platform posing the highest possible level of risk to the public. 

This determination is made based on broadly-drafted criteria about the number of visitors to a website and certain basic organizational features, like the ability to forward content. As a Category 1 service, Wikipedia could face the most burdensome compliance obligations, which were designed to tackle some of the UK’s riskiest websites. 

To demonstrate just how vague the criteria currently are, consider the ability to forward content. Under the Categorisation Regulations, even functions on Wikipedia that allow users to choose the daily “Picture of the day” — such as the one below — currently increase the risk of Wikipedia falling into Category 1.  

Wikipedia simply does not operate like other Category 1 sites. Someone reading an online encyclopaedia article about a historical figure or cultural landmark is not exposed to the same level of risk as someone scrolling on social media. Wikipedia does not advertise; does not sell personal data; and it does not operate for profit. 

The Foundation’s sole objective is to allow people to participate in the creation and dissemination of free, verifiable knowledge. The Category 1 duties threaten that, for example, by disempowering users who wish to keep their identity private. And, as a nonprofit funded almost entirely by donations, it would be a substantial challenge to our resources to meet the strict reporting and compliance obligations. Failure to meet these obligations would mean we risk being fined, or worse, blocked, leaving internet users in the UK without the ability to create or access knowledge on Wikimedia projects. 

This categorisation doesn’t make sense. Not for Wikimedia, and not for the world. That’s why we are challenging the OSA’s Categorisation Regulations.

What happens next?

The Categorisation Regulations must be challenged rapidly in the courts. There is a short timeline as UK regulators are already demanding that we provide the information they need to make a preliminary Category 1 assessment for Wikipedia. We are therefore asking for expedited hearings. At the same time, we will continue to urge the UK government and regulators to make improvements, perhaps even before a judge has to rule on the case. 

As the UK government works to protect the public from the harms of the internet, we hope it also prioritizes protecting the best parts of the internet: public interest projects like Wikipedia that uplift civil society and promote access to free and open knowledge online.