In the August 2019 survey we received responses from 1,271,920,923 sites across 239,441,736 unique domain names and 8,948,887 web-facing computers. This reflects a large loss of 124 million sites, but a gain of 1.30 million domains and 10,700 computers.

All major vendors lost active sites this month, and of those, only Google made a gain in sites (+1.58 million). Microsoft lost the largest number of active sites (-2.03 million), while nginx lost the most sites (-81.4 million, -16.9%) but remains in the lead with a 31.6% share of all sites.

Despite losing so many sites, nginx showed the strongest growth in unique domains, web-facing computers, and among the top million sites. This bears more significance than the more unpredictable changes in the site counts, which are prone to fluctuations month-on-month as link farms, spam networks and other low-value web content comes and goes.

With a gain of 58,500 web-facing computers, nginx now has more than 31% of the computer market share – just 5.39 percentage points behind Apache – while Microsoft has lost 65,000 computers. As is evident in the graphs, counting web-facing computers provides the most stable metric and makes long term trends easy to spot. In particular, the clear and consistent rise in nginx's market share and the steady decline of Apache makes it hard not to imagine nginx taking the market lead from Apache by early next year.

The number of top-million websites powered by nginx has increased by 1,292, while Apache's count fell by 3,101. Apache maintains the lead in this market, but is now only 5.92 percentage points ahead of nginx. Apache also continues to lead in terms of unique domains, despite losing 784,000 this month. It has a similar lead over nginx, which is now only 5.32 percentage points behind Apache after gaining 753,000 domains.

Microsoft lost counts in almost all metrics this month, apart from where it gained 166,000 domains, although this still resulted in a small drop in its domain market share. The sites market is the only one where its share did not fall, despite losing 16.6 million sites.

Netflix finds nginx vulnerabilities

nginx 1.61.1 stable and nginx 1.17.3 mainline were released on 13th August, in order to address three HTTP/2 security issues that could cause excessive memory consumption and CPU usage. All versions between 1.9.5 – 1.17.2 are affected, but only if HTTP/2 is enabled. These security issues were discovered by Jonathan Looney at Netflix, which chose to use nginx when developing its own globally distributed content delivery network, known as Netflix Open Connect.

The content delivery network consists of Open Connect Appliances, which run the FreeBSD operating system and use nginx to stream audio and video directly to Netflix customers. Most of this content is served from appliances hosted by ISPs, rather than across the internet, which leads to better performance whilst vastly reducing the amount of peered traffic when huge numbers of customers worldwide stream a popular show at the same time. Thousands of ISPs have enthusiastically participated in this program because it is free to connect to the Open Connect network, and it prevents Netflix traffic from taking up a significant amount of an ISP's internet capacity.

FreeBSD is dying?!

Netflix chose FreeBSD for its balance of stability and features (as did Netcraft once upon a time), but it is becoming an increasingly less common frontend operating system on the web as a whole. Only 60,200 (0.67%) web-facing computers are running FreeBSD today. To put this into perspective, more than twice as many servers are still running Windows Server 2003, even though it has not been supported for several years.

Linux is by far the most commonly used operating system for web-facing computers. It is installed on 6.64 million (74.2%) servers, and at least 1.05 million of these can be positively identified as running the Ubuntu distribution.

Naturally, the choice of operating system depends to some extent on what type of web server will be running on it, and vice versa. For example, it is no surprise that most instances of Microsoft IIS can be found running on Windows Server, and most instances of Windows Server are used to run Microsoft IIS; but it is clear that the Linux operating system is especially favoured for some web servers. Between 92% and 96% of all web-facing computers that use each of nginx, Apache, Litespeed and lighttpd can be found running Linux.

AWS ELB overtakes Beaver

The awselb (Amazon Web Services Elastic Load Balancing) web server was found on 69,800 web-facing computers this month, overtaking Beaver to become the fourth most commonly used frontend server by computers. Practically all of these machines appear to be running Linux, and are responsible for hosting 464,000 sites across 48,500 unique domains.

ELB achieves fault tolerance and scalability by automatically distributing incoming application traffic across multiple targets – and can even spread it across multiple AWS Availability Zones – so the 69,800 AWS ELB servers exposed to the internet are likely to be only the tip of the iceberg in terms of the AWS infrastructure used by each website.

In the July 2019 survey we received responses from 1,395,897,118 sites across 238,145,990 unique domain names and 8,938,144 web-facing computers. This reflects gains of 62.5 million sites, 1.15 million domains, and 98,000 computers.

nginx continues to extend its lead at the top of the list of web server vendors by total number of sites: it has gained 43.3 million sites since the June 2019 survey, bringing its total to 483 million. It now leads second-place Apache by 6.84 percentage points.

nginx has achieved the milestone of serving more than a third of sites in the survey. It becomes the fourth web server to achieve this in the 24 years since Netcraft's Web Server Survey began in August 1995. At that time NCSA [archive.org] - one of the very earliest web servers - served 53% of all sites. NCSA was quickly replaced by Apache, which passed the one-third milestone in June 1996 and continued to serve more than a third of sites until February 2016. Microsoft have served more than a third of sites for four separate periods most recently falling below a third in January 2019.

Unusually, nginx did not fare as well in any of the other metrics this month, losing out in both absolute numbers and market share in terms of domains (-4.0 million, -1.81pp), active sites (-1.2 million, -1.00pp) and in the top million busiest sites (-9,300, -0.93pp). The drops in domains and active sites are accounted for by large changes at two hosting providers; 2.8 million domains hosted by Endurance International Group moved from using nginx to Apache, and 1.5 million domains and 1.4 million active sites hosted by ecommerce provider Shopify now identify as using cloudflare. nginx also lost a small amount of market share of web-facing computers (-0.10pp) despite gaining 21,300 in absolute terms. These losses buck the trend of recent months that has seen nginx gaining market share from Apache and Microsoft.

Apache gained both the largest number of domains and the largest number of active sites since the June survey with increases of 2.2 million and 2.1 million respectively. Microsoft gained the largest number of web-facing computers with an increase of 43,200.

Cloudflare's web server moves up another place into fourth this month after gaining 4.7 million sites to bring its total to 39.9 million. It serves 9.5 million more sites than fifth placed openresty, but stands well behind the 190 million sites served by Microsoft's IIS. The 39.9 million sites served using Cloudflare are spread across 15.2 million unique domains, 2.6 sites per domain, a significantly smaller number of sites per domain than the top three placed web servers. Nginx has 8.2 sites per domain, Apache has 5.3, and Microsoft IIS has 9.3; the total for all sites in the survey is 5.8 sites per domain.

Envoy - the open source edge and service proxy for cloud-native applications, which leapt up to the tenth largest web server by sites in the May survey - has dropped over 200 places and is only seen hosting 13,000 sites in the July survey. This comes as a result of Squarespace sites no longer identifying themselves as using Envoy, but rather announcing "Squarespace" as the web server. Squarespace is the eleventh largest web server by number of sites with 5.2 million sites on 2.8 million unique domains; the seventh largest number of domains.