Global Cloudflare Outage Disrupts Millions of Websites

On Tuesday, 18 November 2025, Cloudflare — the U.S. firm that routes traffic for millions of sites — experienced a sudden failure that produced error messages across the internet. The incident was first reported at 11:48 a.m. London time. By 2:48 p.m., the company announced that a fix had been applied and the outage was “now resolved,” while it continued to monitor services for residual errors. During the disruption, users of Cloudflare’s encryption service Warp in London received “failure to connect” messages, and site owners could not reach performance dashboards. High-profile customers such as X and OpenAI reported increased downtime.

The Guardian

Cloudflare provides protection against distributed denial-of-service attacks, traffic monitoring, and human-verification services for websites, apps, APIs, and AI workloads. The outage followed an Amazon Web Services failure less than a month earlier that knocked thousands of sites offline, underscoring the concentration of critical internet infrastructure in a small number of providers.

The Guardian

A Cloudflare spokesperson apologized to customers “and the internet in general for letting you down today,” and pledged to “learn from today’s incident and improve.” The company explained that an automatically generated configuration file for threat-traffic management had grown beyond its expected size, causing a crash in the traffic-handling software. Cloudflare said some services might experience brief degradation as traffic spikes post-incident but expected full restoration within hours.

The Guardian

Prof Alan Woodward of the Surrey Centre for Cyber Security described Cloudflare as “the biggest company you’ve never heard of” and a “gatekeeper” that monitors traffic to defend sites from malicious overloads. He noted that the outage highlighted how few firms underpin the internet, making failures immediately visible.

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

• “Users in London trying to access the internet via Warp will see a failure to connect.” — Cloudflare spokesperson

The Guardian

• “was a configuration file that is automatically generated to manage threat traffic” — Cloudflare spokesperson

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