For hours, websites worldwide have been inaccessible or loading very slowly. The cause appears to be an outage of the American service Cloudflare, on which large parts of the internet rely. WELT answers the most important questions.

Anyone browsing the internet on Tuesday afternoon saw that many websites and services displayed only an error message from the service provider Cloudflare instead of the usual offerings: "Internal Server Error," followed by "Visit cloudflare.com for more information." An infographic illustrated the problem: A so-called cache server from Cloudflare very often stands between the actual servers of the providers, the website operators, and the user.

The global network of the US service provider is designed to accelerate the internet, stabilize connections, and ensure the availability of websites during attacks. Numerous companies, media outlets, and online shops route their data traffic through Cloudflare's globally distributed servers to minimize loading times and make data traffic more efficient.

But woe betide anyone if something goes wrong at Cloudflare itself – then it feels like half the internet stops working. Around 40 million websites and services worldwide rely on the service, including prominent social media networks like X and tech companies like OpenAI, as well as many government and agency websites, especially in the US. This was one of the reasons why ChatGPT was temporarily unusable.

What happened?

Around 12:30 PM German time, Cloudflare stopped functioning normally, and since then, outages have become increasingly frequent across the network. At 12:48 PM, Cloudflare itself admitted to having identified a problem. The outage reporting service isitdownrightnow.com has since shown problems for Outlook.com, X, Reddit, and PayPal, among others. Despite the error message, Cloudflare's German website provides no further information about the cause of the outage.

The status log on the US website of the service provides more information: They have identified the problem and are working on a solution. A service restart was promised in the meantime – but even two hours later, Cloudflare internet is still experiencing slowdowns.

What is the significance of Cloudflare for the internet?

Cloudflare is one of the invisible cornerstones of the modern internet and currently serves as an example of how closely efficiency and vulnerability are intertwined. The US company protects websites from attacks, accelerates data traffic, and filters malicious code from billions of connections daily.

It is precisely this central role that makes Cloudflare a so-called"single point of failure", which contradicts the basic idea of the internet's resilience to failure through multiple connections: If the service fails, an entire part of the network comes to a standstill.

How does Cloudflare work?

Cloudflare's cache servers bring frequently loaded data, such as from media sites, closer to the user. Conversely, an outage leads to worldwide disruptions. The balancing act between security and dependency thus becomes the central challenge of the digital age: a corporation that is supposed to make the network more stable can, in a worst-case scenario, become its own Achilles' heel.

The latest incident also highlights the increasing concentration of services on the internet. The more online services rely on a few large providers, the more vulnerable the network becomes. Just a month ago, Amazon AWS, a major cloud service, suffered an outage, and thousands of online services, some of them large, were temporarily offline.

Today's Cloudflare outage vividly illustrates just how fragile some parts of the digital nervous system truly are. A single globally distributed service can cripple entire platforms, applications, and even government infrastructures. This outage is therefore also a lesson in digital resilience: in times of crisis, when everyone relies on a single service provider, this inherently poses a problem.

What are the consequences of the outage for Cloudflare?

Cloudflare is a publicly traded company. Its stock had risen sharply in recent months: at the end of October, the price was around 150 percent higher than twelve months earlier. On Tuesday, after news of the outage broke, the stock fell sharply even before the US stock market opened. Cloudflare temporarily lost around five percent.

Cloudflare's strong increase in value over the past few months is also due to the company's AI strategy: Cloudflare will not allow AI companies' crawlers to access its customers' content if they are not paying for access. This makes it more difficult for AI companies like OpenAI, Anthropic, and Perplexity to train their language models.