Operating in 90 countries and working with over one billion unique IP addresses, Cloudflare has grown into a web infrastructure and security giant. Many people come across Cloudflare as an annoyance – websites will briefly show a holding screen while the main page loads, indicating the request is being ‘checked’ by Cloudflare’s anti distributed denial of service (DDoS) tools. What they might not know is that this is a vital service, without which many of the world’s largest websites would be vulnerable to outages.

A distributed denial of service (DDoS) attack occurs when the attacker floods a website with repetitive spam requests and overwhelm its resources, rendering it unavailable to the intended users. Large DDoS attacks have hit major tech companies such as Google and Amazon, sometimes putting their services out of use for hours or even days. Some of the most infamous computer viruses in history have been designed to launch DDoS attacks – most notoriously the 2004 DDoS attack launched by ‘Mydoom’, a worm accounting for 20% of all email traffic at its peak. Given the scale of the problem, anti-DDoS tools are an essential service.

Cloudflare was founded in 2009 by Matthew Prince, Lee Holloway, and Michelle Zatlyn, then employees at the anti-fraud network Project Honey Pot. Originally developed out of software to track suspicious emails, its first tools were launched a year later, attracting 10,000 customers within their first month. Initial funding came from venture capitalists Venrock and Pelion Venture Partners. In the beginning, one of the founders’ main concerns was that using Cloudfare tools would slow down their client’s websites; fortunately for Cloudflare, most of their early clients instead noticed the opposite, with protection offering the unexpected benefit of shorter load times. On average, Cloudflare claims websites using its network load twice as fast, whilst benefiting from protection against comment spam, DDoS, and other security threats.

By 2020, Cloudflare was handling 10% of all Internet requests, but the company’s growth has not been without controversy. Cloudflare has faced criticism for offering its services to hackers themselves, and for the first time in 2018 cut ties with certain clients over alleged involvement in the organization of mass shootings. This took place against the backdrop of increased scrutiny in the run-up to the company’s 2019 IPO. Cloudflare went public on the New York Stock Exchange, trading under the ticker ‘NET’ at an initial price of $15 per share. The IPO was considered highly successful, and the stock remains popular with institutional shareholders. The largest investors are Blackrock, Baillie Gifford, and Morgan Stanley.