Global Cloudflare Outage Disrupts Internet Access Worldwide

On Tuesday, 18 November 2025, Cloudflare reported a global service interruption that began at 11:48 a.m. London time. The failure produced error messages on many websites, including X and OpenAI, and blocked some site owners from viewing performance dashboards. During the incident, Cloudflare disabled its Warp encryption service for London users, causing additional connection failures. By 2:48 p.m., Cloudflare said a fix was applied and services were expected to normalize, though brief degradation might follow as traffic rebounded.

The Guardian

Cloudflare, a U.S. firm, offers DDoS protection, traffic monitoring, and performance acceleration for websites, APIs, and AI workloads. Its services act as a “gatekeeper” for a large share of web traffic, verifying human users and mitigating malicious spikes. The outage follows an Amazon Web Services disruption less than a month earlier, highlighting the concentration of critical internet infrastructure among few providers.

The Guardian

The trigger was an automatically generated configuration file for threat-traffic management that exceeded its intended size, causing a crash in the traffic-handling software and the observed service failures. Cloudflare expects only short-lived degradation as traffic spikes during post-incident recovery.

The Guardian

The incident showed how reliance on a single provider can cause visible, worldwide disruptions. Commercial platforms and AI research services faced reduced accessibility, highlighting systemic risk from limited redundancy in core networking services. Downdetector, a monitoring service, recorded the outages.

The Guardian

A Cloudflare spokesperson apologized to customers and the internet community, saying the company would monitor for errors and restore services promptly.

The Guardian

Prof. Alan Woodward of the Surrey Centre for Cyber Security called Cloudflare “the biggest company you’ve never heard of” and warned that the sector’s concentration makes failures immediately apparent. He labeled the firm a “gatekeeper” and noted that the few infrastructure providers amplify the impact of any single outage.

The Guardian

• “A fix has been implemented and we believe the incident is now resolved. We are continuing to monitor for errors to ensure all services are back to normal.” — Cloudflare spokesperson

The Guardian

• “We will learn from today’s incident and improve.” — Cloudflare spokesperson

The Guardian

• “This file grew beyond its expected size and triggered a crash in the software system that handles traffic for a number of Cloudflare’s services.” — Cloudflare technical statement

The Guardian

• “the biggest company you’ve never heard of” — Prof. Alan Woodward, Surrey Centre for Cyber Security

The Guardian

• “We’re seeing how few of these companies there are in the infrastructure of the internet, so that when one of them fails it becomes really obvious quickly,” — Prof. Alan Woodward

The Guardian

Cloudflare will monitor traffic spikes after the fix and review its configuration-file generation to prevent recurrence. Observers say the outage may spark broader debate on diversifying critical internet infrastructure.

The Guardian