Operations | Monitoring | ITSM | DevOps | Cloud

On November 18th, 2025, a large Cloudflare outage briefly broke big chunks of the internet. For several hours, users around the world were greeted with 500 errors, including platforms like X, ChatGPT, Spotify, and many others that run behind Cloudflare’s network. At UptimeRobot, we sit in a slightly unusual spot during events like this: So when Cloudflare has a bad day, we see it twice: once in the alerts we send to our customers, and again in how it affects parts of our own infrastructure.

Having just returned from the 2025 EDUCAUSE Annual Conference in Nashville, I want to share some insights on the future of campus IT from the higher education technology leaders in attendance. Every year, this conference provides an opportunity for technology providers and higher ed professionals to connect and explore the latest innovations in higher education technology. Two themes emerged as critical priorities.

On November 18, 2025, X, ChatGPT, Shopify, and many other major sites went offline simultaneously. Even Downdetector, Ookla’s popular outage tracking website, briefly went offline. What caused this issue? Why were so many major websites affected by it? And what steps can you take to reduce the impact on your own applications? ‍

The hidden blockers slowing down your incident response and how to remove them before they become reliability risks. Incidents rarely go wrong because of one big failure. Most of the time, it’s a handful of small, familiar mistakes that slow teams down, muddy communication, or create confusion in the heat of the moment. Fortunately, these mistakes are predictable and fixable.

As major incidents like AWS’s October 2025 outage illustrate, modern systems are immensely interconnected. A failure in one can lead to a cascade of downstream problems. In this case, issues with DNS resolution for DynamoDB led to widespread disruptions with other AWS services and, subsequently, thousands of applications and services that rely on that infrastructure.

Cloudflare-like outages can cost your business a significant amount of money. This week’s Cloudflare global outage is a wake-up call for business resilience. You can stay resilient against such outages by regularly performing resilience testing and updating your application or infrastructure configurations.

When external providers fail—whether it was CrowdStrike outage last year, AWS outage last month, or the Cloudflare DNS outage yesterday—the symptoms inside your environment often look like internal issues: timeouts, login failures, API errors, service degradation, or sudden spikes in dependency-related alerts. It’s natural for teams to start searching through their own infrastructure first, but none of these symptoms clearly point to your systems as the root cause.

On 2025-11-18 at 11:48 UTC, Cloudflare declared an incident affecting the global network (that also affected OnlineOrNot). OnlineOrNot monitors websites, APIs, web apps, and cron jobs, while providing status pages as well. While we partially mitigated the issue by enabling a fallback to AWS-based monitoring, between 13:00 UTC and 14:33 UTC failing checks went unreported, heartbeat checks over-reported, and status pages were unavailable.

Yesterday’s widespread Cloudflare outage reminds us how crucial external dependencies are to the stability of our own applications. When a key edge provider like Cloudflare goes down, the impact on your internal monitoring systems can look like a catastrophic, internal system failure triggering a massive storm of alerts and sending engineering teams into frantic, misdirected debugging sessions.