Explainer: What is Cloudflare?
It remains unclear how many of those sites were affected by today’s outage or the scale of the disruption.
Cloudflare is one of the world's largest internet security service providers, offering tools that help websites verify whether incoming traffic is from genuine users or automated bots.
According to the company, around 20% of all global websites use its services in some capacity.
However, it remains unclear how many of those sites were affected by today's (18 November) outage or the scale of the disruption.
Keep updated, follow The Business Standard's Google news channel
Even Downdetector, a platform widely used to track service outages, briefly displayed error messages as user traffic surged.
Alp Toker, director of internet watchdog NetBlocks, described the incident as a "catastrophic disruption" to Cloudflare's infrastructure.
He noted that many websites have come to depend on Cloudflare to protect against large-scale denial-of-service (DDoS) attacks.
"Due to its convenience and widespread use, Cloudflare has effectively become one of the internet's largest single points of failure," Toker told the BBC.
The Cloudflare disruption follows a series of recent outages involving major web service providers.
Last month, an Amazon Web Services (AWS) outage knocked more than 1,000 websites and apps offline. Shortly afterwards, Microsoft Azure also faced technical issues.
"These incidents underline the growing dependence on fragile but critical networks," said Jake Moore, global cybersecurity advisor at ESET.
"Businesses have little choice but to rely heavily on providers such as Cloudflare, Microsoft, and Amazon, as alternatives remain limited," he added.
