The Cloudflare Outage That Broke the Internet

November 18, 2025 — At approximately 5:20 AM ET this morning, a significant portion of the internet simply stopped working. Users attempting to access X (formerly Twitter), ChatGPT, Spotify, Shopify, and thousands of other popular websites were met with error messages stating their connection was fine, their device was working, but Cloudflare services were experiencing issues.

The culprit? A single configuration file that grew too large.

The Scale of the Disruption

Cloudflare, which powers approximately 19% of all global websites, suffered what the company called "widespread 500 errors" affecting its Dashboard and API services. The impact was immediate and extensive, touching nearly every corner of the digital world.

Major platforms affected included:

• Social media: X (with over 9,700 outage reports at its peak)

• AI services: ChatGPT, Claude chatbot, OpenAI's Sora video app

• Entertainment: Spotify, League of Legends, multiplayer gaming services

• E-commerce: Shopify, Coinbase

• Professional services: Indeed job search, Moody's credit ratings

• Government: Scottish Parliament website

• Transportation: NJ Transit digital services, Uber and Uber Eats

• Even critical infrastructure: PADS background check system for nuclear plant visitor access

The irony wasn't lost on frustrated users: DownDetector itself, the website people turn to during outages, was also knocked offline by the Cloudflare issues. One user quipped on social media: "Can't find out if Cloudflare is down because Cloudflare being down has taken out DownDetector, along with half the internet."

The Root Cause

According to a Cloudflare spokesperson, the root cause was "an automatically generated configuration file used to manage threat traffic that grew beyond an expected size of entries," triggering a crash in the software system handling traffic for several services.

The company began observing a "spike in unusual traffic" around 5:20 AM ET, though there's no evidence the outage resulted from an attack or malicious activity. The spokesperson emphasized: "Given the importance of Cloudflare's services, any outage is unacceptable. We apologize to our customers and the internet in general for letting you down today."

The timing raised questions, as scheduled maintenance in Cloudflare's Santiago datacenter was planned for the same time of day, though the company hasn't confirmed any connection between the maintenance and the global outage.

The Financial Impact

According to website maintenance service SupportMy.website, an estimated $5 billion to $15 billion was lost for every hour of the outage. With the disruption lasting approximately four hours before services were substantially restored, the total economic impact could reach $20-60 billion.

Shares of Cloudflare dropped more than 2% following the incident, though the company's swift response and transparent communication may have prevented more severe market reactions.

For businesses relying on Cloudflare's services, the outage meant:

• E-commerce transactions couldn't be completed

• Customer service platforms were inaccessible

• Marketing campaigns and product launches were derailed

• Employee productivity ground to a halt as essential tools stopped working

• Real-time services like ride-sharing faced disruptions

The Timeline of Chaos

5:20 AM ET: Cloudflare begins observing unusual traffic spike

7:00 AM ET: Company publicly acknowledges "internal service degradation" with some services "intermittently impacted"

7:45 AM ET: Peak disruption period as thousands of websites become completely inaccessible

8:30 AM ET: Cloudflare identifies a fix but warns of continued impact during implementation

9:57 AM ET: Cloudflare announces "a fix has been implemented and we believe the incident is now resolved," though some users may still experience dashboard access issues

10:30 AM ET: Most services return to normal, though intermittent errors continue

Afternoon: Cloudflare continues monitoring system recovery, with errors and latency returning to normal levels

A Pattern of Fragility

The outage follows recent internet failures from Amazon Web Services (AWS) and Microsoft's Azure. Just last month, AWS experienced a problem caused by issues with companies connecting to its data services in the United States, impacting internet services worldwide. In July 2024, a faulty software upgrade by cybersecurity firm CrowdStrike caused a widespread outage that temporarily halted flights, impacted financial services, and pushed hospitals to delay procedures.

Graeme Stewart, head of public sector at cybersecurity company Check Point, noted: "During today's outage, news sites, payments, public information pages and community services all froze. That was not because each organisation failed on its own. It was because a single layer they all rely on stopped responding".

Alan Woodward, professor of cybersecurity at the University of Surrey, explained the fundamental vulnerability: "The downside of being a gatekeeper and distribution network for such big brands is that if this vital system fails, no one can use your service be that website or app."

What Cloudflare Actually Does

For many internet users, today's outage was their first awareness of Cloudflare's existence, despite using its services dozens of times daily. Cloudflare provides internet infrastructure services to companies across the world, usually doing so in a way that is invisible to users.

The company offers:

• DDoS Protection:

  Shields websites from distributed denial-of-service attacks

• Content Delivery Network (CDN):

  Speeds up website loading by distributing content across global servers

• Web Application Firewall:

  Protects against malicious traffic and hacking attempts

• DNS Services:

  Translates domain names into IP addresses

• Bot Management:

  Distinguishes legitimate users from automated bots

• SSL/TLS Encryption:

  Secures data transmission between users and websites

These services operate seamlessly in the background until they don't. When they fail, as they did today, the cascading effects expose how much of the modern internet depends on a handful of critical infrastructure providers.

The Centralization Problem

As one analyst noted, "it isn't quite as devastating as the recent AWS outages, it's still an example of how much of the web is propped up by a handful of well-meaning services".

The centralization of internet infrastructure creates concerning vulnerabilities:

Single Points of Failure: When one provider controls services for thousands of sites, a single technical problem can cascade across the entire internet ecosystem.

Security Targets: "Any platform that carries this much of the world's traffic becomes a target. Even an accidental outage creates noise and uncertainty that attackers know how to use," Stewart warned.

Limited Alternatives: Many businesses have few viable alternatives to major infrastructure providers, creating lock-in effects that increase vulnerability.

Complexity: As systems grow more interconnected, unexpected interactions between components can trigger failures that are difficult to predict or prevent.

Business Continuity Lessons

Today's outage reinforced critical lessons for businesses operating online:

Dependency Mapping: Organizations must understand their complete dependency chain. If your website depends on Cloudflare, which depends on specific DNS providers, which depend on particular data centers, you need visibility into every link.

Redundancy Planning: Relying on a single infrastructure provider, no matter how reliable, creates unacceptable risk. Multi-cloud strategies and failover systems become not luxuries but necessities.

Communication Protocols: Companies need predefined communication strategies for when primary channels fail. If your customer service platform goes down, how do you inform customers and maintain operations?

Testing and Simulation: Regular disaster recovery drills that simulate infrastructure provider failures help identify vulnerabilities before real crises strike.

Cost-Benefit Analysis: The savings from consolidating on a single provider must be weighed against the potential costs of extended outages, which today's incident shows can reach billions per hour.

The Human Element

Beyond financial losses and technical analysis, the outage revealed how deeply internet infrastructure weaves into daily life. Users reported:

• Unable to order lunch as McDonald's self-service kiosks displayed Cloudflare errors

• Remote workers locked out of essential tools, unable to complete time-sensitive projects

• Students unable to access educational platforms during critical assignment deadlines

• Small businesses watching revenue evaporate as e-commerce sites remained offline

• Gamers disconnected from online multiplayer matches mid-game

The frustration extended beyond inconvenience to genuine concern. One Reddit user posted a photo of a nuclear plant background check system displaying Cloudflare errors, highlighting that even critical infrastructure depends on these centralized services.

Cloudflare's Response

To the company's credit, its response demonstrated several best practices:

Rapid Acknowledgment: Cloudflare publicly confirmed issues within two hours of first detection, rather than attempting to minimize or hide problems.

Transparent Updates: The company's status page provided regular updates throughout the incident, helping customers and users understand the situation.

Root Cause Disclosure: Unlike some providers that remain vague about failures, Cloudflare explained the specific technical cause.

Sincere Apology: The spokesperson's statement acknowledged the seriousness of the incident without making excuses: "Any outage is unacceptable. We apologize to our customers and the internet in general for letting you down today."

Commitment to Learning: The company promised to "learn from today's incident and improve," suggesting forthcoming analysis and preventive measures.

What Happens Next

The immediate crisis has passed, but the incident raises important questions about internet infrastructure's future:

Regulatory Scrutiny: Should governments impose requirements on critical infrastructure providers regarding redundancy, testing, and resilience?

Industry Standards: Will today's outage accelerate development of industry-wide standards for infrastructure provider reliability and transparency?

Decentralization Movement: Could incidents like this accelerate interest in decentralized internet architectures that distribute risk rather than concentrating it?

Customer Demands: Will businesses demand more robust service level agreements and penalty clauses for major outages?

Technical Architecture: How can infrastructure providers design systems that fail more gracefully, allowing partial functionality rather than complete shutdowns?

The Bigger Picture

Today's outage serves as a stark reminder of modern internet infrastructure's fragility. A single configuration file growing too large triggered a cascade that affected billions of users worldwide, disrupted countless businesses, and exposed the vulnerability created by centralized internet services.

As Professor Woodward noted, being a gatekeeper comes with enormous responsibility. When that gate fails, the internet doesn't slow down—it stops. For the estimated 19% of websites depending on Cloudflare, four hours of downtime meant four hours of complete disconnection from their users.

The incident also highlights a paradox: the same centralization that enables incredible efficiency, speed, and cost-effectiveness also creates catastrophic failure points. Cloudflare's services make the internet faster, more secure, and more reliable 99.9% of the time. But that remaining 0.1% can have outsized impact when it affects such a large portion of the web.

Moving Forward

For businesses and internet users, today's outage offers crucial lessons:

• Diversification matters:

  Don't put all your infrastructure eggs in one basket

• Visibility is essential:

  Understand your dependency chains

• Redundancy costs money but outages cost more:

  The $5-15 billion per hour calculation makes backup systems look inexpensive

• Communication plans need backups:

  If your primary channels depend on the same infrastructure as your services, you'll be silenced when you most need to speak

• The internet's architecture needs rethinking:

  A handful of providers shouldn't control the fate of billions of users

As we return to our regularly scheduled browsing, posting, and working, the question lingers: How many similar single points of failure exist across our digital infrastructure, waiting for their configuration file to grow too large?

The answer should concern us all.