In the February 2018 survey we received responses from 1,838,596,056 sites across 214,036,874 unique domain names and 7,290,968 web-facing computers. This reflects a gain of 63,000 computers, and nearly a million additional domains. Overall hostname growth was 33 million, and the number of active sites grew by 9.3 million.

Microsoft dominated this month's domain growth, with an extra 1.1 million domains (+2.0%) taking its market share up by 0.41 percentage points to 26.5%, while Apache lost 115,000 domains. Microsoft also saw the largest hostname growth, with an additional 59 million sites taking its leading hostname share up by 2.65 points to 34.5%.

After excelling in all growth metrics last month, nginx did not sweep the board this time. Although its computer growth continued to be strong – gaining 44,000 this month – it lost 11.2 million hostnames globally. The primary cause of this was more than 15 million sites switching from nginx to Apache. Most of these sites were previously hosted by Raksmart in China, but are now hosted by Data Foundry in the United States.

All four of the largest major vendors – Apache, nginx, Google and Microsoft – gained active sites this month. Apache made the largest gain of 2.1 million, but this was not enough to prevent its active sites share falling by 1.1 points to 42.7%. Nonetheless, Apache continues to lead with more than twice as many active sites as its closest competitor, nginx.

Cloudflare-nginx migration underway

For several years, every edge machine in Cloudflare's content delivery network (CDN) exhibited the Server: cloudflare-nginx HTTP response header. This reflected the fact that its custom software stack was based on nginx – but this month's survey saw a vast swathe of websites switching to a new Server: cloudflare header.

Although nginx remains part of Cloudflare's stack, it plays less of a role than it once did. The code that handles HTTP requests on Cloudflare's machines now goes far beyond the capabilities of nginx alone, and Cloudflare also hints that it will most likely end up writing its own caching software instead of using nginx.

In line with Cloudflare's reasoning, Netcraft's survey treats the new cloudflare server as a distinct product to nginx, and this has taken a chunk out of nginx's share in the top million sites. The new cloudflare server already accounts for 5.2% of the top million sites, and this share will undoubtedly increase next month.

The transition to the new cloudflare server banner started on 18 December 2017, and the February 2018 survey found nearly 60% of Cloudflare's sites using the new banner. It is likely that they will all use the new banner by next month's survey.

Other web server news

The developers of nginx have added support for HTTP/2 Server Push, which is likely to be made available in the next release. This feature allows web servers to send resources such as images and stylesheets before they are requested by the browser, which can make some webpages load faster.

After coming to prominence last month, DPS is now the 9th largest server by domains. It continues to be used almost exclusively by GoDaddy to host sites created with its Website Builder tool, and it is still being regularly updated. The current version in use at the time of writing is DPS 1.2.1, whereas a month ago it was 1.1.20.

OpenLiteSpeed 1.5.0 RC1 was released on 2 February, adding new Multi-Thread APIs and a module developer guide. This followed the 10 January release of 1.4.29, which is currently the latest stable version of the freely available open source server. Just over 2.5 million domains are currently using OpenLiteSpeed or the commercially available LiteSpeed Web Server product. Both products use the same LiteSpeed server banner and do not reveal version numbers.

Finally, NGINX Unit saw a few new releases since the last survey. NGINX Unit 0.4 was released on 15 January. This was the first release of the lightweight web application server to be compatible with DragonFly BSD, but it was mostly a bugfix release that eliminated some significant regressions in the previous version. NGINX Unit 0.5 was then released on 8 February, adding a Perl application module that allows it to run applications like Bugzilla; however, this release was not announced, as it contained a serious regression that could cause the main process to die. This was rectified in NGINX Unit 0.6, which was announced on 9 February.

In the January 2018 survey we received responses from 1,805,260,010 sites across 213,053,157 unique domain names and 7,228,005 web-facing computers. This reflects a gain of 214,000 computers, but only 183,000 domains. Overall hostname growth was 71 million, although the number of active sites fell slightly, by 311,000.

DPS powering GoDaddy's Website Builder

While the total number of domains across all web server vendors grew slightly, 1.5 million fewer domains used a Microsoft web server in the January 2018 survey. Its share of domain names has fallen by 0.74 points to 26.1%. Contributing to that loss were more than 985,000 unique domains hosted by GoDaddy, which are now using a lesser-known web server called DPS.

DPS (Data Protection Server) is now the 10th largest server by domains, and it is used exclusively by GoDaddy to host customer sites that have been created with its Website Builder tool. The DPS server appears to be frequently updated: sites using it currently return the Server: DPS/1.1.20 header, but these sites were using version 1.1.19 when the data was collected for the January 2018 survey. In the December 2017 survey, the sites were using version 1.1.16, and 1.1.10 in November 2017.

Cloud balancing with Pepyaka and F5 BIG-IP

Another lesser-known server, Pepyaka, also saw massive domain growth at a single hosting company this month. The Israeli web development platform Wix uses Pepyaka to host its customers' sites in the Amazon Web Services cloud, but many of these sites did not identify which server software they were using during the previous survey, causing a temporary absence. The number of domains using Pepyaka at AWS is now back up to more than 1.8 million, making it the 6th largest server by domains.

Nearly all of the Wix sites hosted at AWS use Pepyaka 1.11.3, which is likely based on the July 2016 mainline release of nginx 1.11.3; but it looks like Wix is in the process of rolling out an updated version: This month saw the appearance of 22 sites using Pepyaka 1.13.4, which most likely corresponds to the August 2017 mainline release of nginx 1.13.4.

Last month's temporary absence of Pepyaka could have been indicative of wider scale experimentation by Wix. Many of Wix's sites were served from machines that exhibited the TCP/IP characteristic of F5 BIG-IP, whereas this month, those sites are back to using Pepyaka running on Linux.

Wix has been a long-time user of nginx, and originally moved all user traffic to the commercial NGINX Plus product to future-proof its load balancing needs. The temporary appearance of F5 BIG-IP demonstrates that Wix may have been testing the waters with a different load balancing setup.

For most of its life, F5 BIG-IP has only been available on specialist hardware devices, such as BIG-IP appliances or VIPRION chassis; but F5's Virtual Editions make it possible to run BIG-IP software on commodity hardware in the cloud. F5 offers several BIG-IP Virtual Edition Amazon Machine Images (AMIs) in the AWS Marketplace, with pay-as-you-go licensing costs ranging from $0.33 to $4.40 per hour.

In May 2017, F5 also announced new public cloud solutions for Azure and Google Cloud, as well as a private cloud solution for the OpenStack cloud platform. This month's survey found more than 13 million domains being served from F5 BIG-IP devices, with Apache being the most commonly seen Server header.

Apache leads in most metrics, but nginx dominates in growth

Across the entire market, Apache remains in the lead with a 38.2% share of domains, but the ongoing trend makes it likely that both Apache and Microsoft could be overtaken by nginx in the next few years. nginx has continued to steadily increase its domain share, with a 0.21 point gain to 20.5% this month, while Apache has been experiencing a general decline of market share in recent years.

nginx's persistent growth has also manifested itself in every other metric this month, with it gaining the largest number of sites, active sites and web-facing computers, as well as increasing its presence amongst the top million sites. nginx is now used by 23.5% of all web-facing computers and 30.5% of the top million sites, but Apache still has the largest number of active sites, computers, domains and top-million sites.

The only metric graphed below in which Apache does not take the lead is hostnames, where Microsoft has a total of 575 million sites; but this metric is prone to fluctuations and is less indicative of market success. Microsoft has the second largest number of domains in the survey, but has been ranked third in web-facing computers since it was overtaken by nginx in October 2017.

While 1.5 million web-facing computers currently run Microsoft web server software, a slightly larger number – 1.8 million – run Windows operating systems. The bulk of the difference is made up of Windows computers that either run Apache or reverse-proxy traffic from backend Apache servers. The most commonly used Windows version is Windows Server 2008, followed by 2012 and then the aging, unsupported Windows Server 2003. Windows Server 2016 accounts for only 3.7% of all Windows web-facing computers at the moment, but it is steadily growing – this month, the number of Windows Server 2016 computers grew by 14% to 66,800.

In the December 2017 survey we received responses from 1,734,290,608 sites across 212,870,632 unique domain names and 7,014,428 web-facing computers. This reflects a gain of 5.34 million domains and 121,000 computers.

Web Server Developers - Market Share of Domains

The number of hostnames in use on the web has been a headline metric since the inception of the Web Server Survey, but it has been subjected to quite large fluctuations in recent years. Netcraft has therefore introduced the number of unique domains as an additional metric that provides a more stable view of the web.

The domains metric is not influenced by wildcarded domains or other large numbers of sites that can be hosted under a single domain name with minimal effort; but unlike the active sites metric, the domains metric still takes account of sites that are still under construction, or running hosting company or domain registrar holding pages.

The noticeable spike in Apache-powered domains in May 2013 was caused by the largest hosting company of the time, GoDaddy, switching a large number of its domains from Microsoft IIS to Apache Traffic Server (ATS) . GoDaddy switched back to using IIS 7.5 a few months later.

Today, Apache still has the largest market share by number of domains, with 81.4 million giving it a market share of 38.2%. It also saw the largest gain this month, increasing its total by 1.53 million. This growth was closely followed by nginx, with a gain of 1.09 million domains increasing its total to 47.5 million. While Microsoft leads by overall number of hostnames, it lags in 3rd position when considering the number of unique domains those sites run on, with a total of 22.8 million.

Web-facing Computers

The number of web-facing computers provides an alternative view that corresponds more closely to the install base of each server vendor.

With 1.63 million web-facing computers, nginx is already 97,800 computers ahead of Microsoft since it took second place in October, but Apache remains much further ahead with a total of 2.98 million. Apache experienced the largest gain of 58,000 computers this month, closely followed by nginx with 49,000, and with Microsoft trailing with an increase of just 22,000.

Web Server Updates

Microsoft's Internet Information Services platform has benefitted from a few improvements since the publication of last month's survey. The newest version of the IIS Administration API (2.2.0) introduced new endpoints that make it easy to monitor the health of a web server, as well as the individual websites and application pools running on it. There is also a new configuration endpoint for the files API, which allows the API's root folders to be configured – this means administrators no longer have to edit a file to configure which sections of the file system can be accessed via the API.

Version 1.0 of the IIS CORS Module, which works on IIS 7.5 or later, was also released in November. This enables support for the Cross-Origin Resource Sharing protocol, which lets webpages make use of resources that are hosted on other websites, such as web fonts and AJAX endpoints. If a website hosts these resources without setting a suitable CORS policy, the default same-origin policy enforced by all browsers would prevent other websites from accessing them.

The latest version of the open source LiteSpeed HTTP server, OpenLiteSpeed 1.4.28 (stable), was released on 8 November. This release adds multithreading APIs for LSIAPI – the API that allows it to support third-party modules. Although there are only 12,400 web-facing computers running LiteSpeed, these computers host 2.42 million domains. It is not clear how many of these computers are already running LiteSpeed 1.4.28, as this server does not expose version information in its headers.

lighttpd 1.4.48 was subsequently released on 11 November. This adds a new mod_authn_sasl module, which provides Simple Authentication and Security Layer (SASL) authentication similar to Apache's libapache2-mod-authn-sasl module. With 20,800 web-facing computers running lighttpd, it has a greater install base than LiteSpeed, but its market share of domains is noticeably smaller with a count of 565,000.

nginx 1.13.7 was released on 21 November, although this addresses several bugs rather than introducing any new features. There are, however, several new features in the latest version of its commercially supported product, NGINX Plus Release 14, which was announced on 12 December. This release features several improvements, including an updated live monitoring dashboard and JSON support in its nginScript scripting language; and there is also a technology preview of its extended clustering support, which lets NGINX Plus instances in a cluster share state information.

In the November 2017 survey we received responses from 1,819,412,110 sites and 6,893,323 web-facing computers, reflecting a gain of 4.17M sites and 6,961 computers.

This month’s web server survey saw Microsoft’s market share amongst all sites fall by 12.64 percentage points due to a loss of 228M sites. Despite this, Microsoft still retains its place with the largest market share by this metric of 36.80%, with Apache trailing at 24.38%. The majority of the loss occurred at just one hosting provider where over 190M Microsoft sites were lost.

This change isn’t reflected in the active sites metric which only saw minor changes amongst the main web server vendors. Microsoft lost only 0.03 percentage points of its market share with a drop of 261k active sites. Apache leads in the active sites metric by a considerable margin, increasing its share slightly this month to 44.55%.

Amongst the top million busiest sites Microsoft experienced a small increase in market share, pausing its general decline in this market. nginx experienced the largest growth with an increase of 2,133 of the top million sites.

nginx also saw the largest increase in number of web-facing computers, gaining 25k and pulling 1 percentage point of market share clear of Microsoft, which it overtook last month. Apache also experienced a gain in computers, albeit smaller at just 7k. It remains considerably ahead with a 42.38% market share.

New gTLDs Seen for the First Time

This month the controversial new .search gTLD being run by Google’s Charleston Road Registry subsidiary was found for the first time, with www.nic.search responding to the survey. Google hopes it will be able to run .search as a dotless domain which will automatically redirect users to their search engine of choice. This proposal has been criticised for going against ICANN’s own rules, which prohibits this functionality due to the potential for conflicts with existing names on internal networks. This feature could also cause confusion for users who have come to expect that typing words into their address bar will perform a search query for that term.

It is currently uncertain whether or not Google will be allowed to run the .search TLD as a dotless domain, however with the launch of the first site on this TLD this month Google is one step closer to the provision of this service.

In the October 2017 survey we received responses from 1,815,237,491 sites and 6,886,362 web-facing computers, reflecting a gain of 10.2 million sites and 88,300 computers.

Web-facing computers: nginx takes second place from Microsoft

nginx made the largest gains in websites, active sites, and web-facing computers this month, as well as increasing its presence among the top million sites. Most notably, the additional 42,100 web-facing computers it gained has taken its total up to 1.55 million computers, putting it ahead of Microsoft for the first time.

Overtaking Microsoft means that nginx is now the second largest server vendor in terms of web-facing computers. With its remarkably consistent growth, nginx is likely to retain this newfound position for some time – not least because Microsoft's web-facing computer share has been on a general decline since 2010.

In the other metrics, nginx gained 18.4 million sites, 941,000 active sites, and slightly increased its share of the top million sites to 29.43%. It stays ranked in 2nd place within the top million sites and active sites, but 3rd in all sites.

While Microsoft's loss of 3,470 web-facing computers helped propel nginx into second place, it made more significant losses in other metrics – it lost 30.1 million sites this month, although this corresponds to a loss of only 85,500 active sites.

New releases

Apache 2.4.29 was released on 23 October. This security, feature and bug fix release represents the latest version of the current 2.4.x branch. As usual, it is recommended over all previous releases, but it is difficult to track how many website administrators take heed of this advice.

For instance, many Apache servers do not reveal via their Server headers or error pages which version has been installed, while others may have been updated with backported patches that do not affect the displayed version number. Consequently, a large number of Apache servers claim to be running older versions than they really are. Only 12.6% of the 341 million sites running Apache claim to be running a 2.4.x release, whereas the true proportion is likely to be much higher, given that almost two-thirds of Apache-using sites do not disclose any version number.

Apache continues to lead the market in terms of active sites and web-facing computers, where it has market shares of 44.5% and 42.3%. It also has the largest presence among the top million sites, with 386,000 of these using Apache.

Another new release this month was LiteSpeed Web Server 5.2.2 (stable), which was released on 17 October. This addresses a couple of bug fixes and improves compatibility with the latest version of the popular cPanel web-based control panel.

As well as its commercially supported LiteSpeed Web Server, LiteSpeed Technologies Inc also provides OpenLiteSpeed, which is freely available under the GPL version 3 licence. LiteSpeed is currently the 7th largest vendor in terms of hostnames and active sites: Nearly 11.5 million sites in the survey are powered by LiteSpeed, and 2.7 million (24%) of these are deemed to be active sites.

One of LiteSpeed's most prominent gains was made in November last year, when a large number of hostnames under the .science top-level domain switched to it from Taobao's Tengine web server. This caused LiteSpeed's market share of sites to leap from 0.39% to 3.29%, although it has since settled back down to 0.63%. Nonetheless, this is still noticeably larger than its share of web-facing computers, which currently stands at 0.17%.

nginx 1.13.6 (mainline) and nginx 1.12.2 (stable) were also released in October. Both releases consist solely of bug fixes.

NGINX Unit

Alongside the new releases of nginx, the nginx.org homepage unusually announced the release of a different product this month: NGINX Unit 0.2 Beta.

NGINX Unit is a lightweight dynamic web application server designed to run applications written in Python, PHP, Go, JavaScript, Java and Ruby, although the current beta release does not support all of these languages, nor does it support TLS, routing or proxying yet.

Precompiled binaries are available for CentOS 7 and Ubuntu 16.04, but as it is a beta release, it is not recommended for use in a production environment. Consequently, it is unlikely to have much of a presence on the web in the near future; also, for performance reasons, it is likely that NGINX Unit would be installed behind a regular nginx web server acting as a reverse proxy.

In the September 2017 survey we received responses from 1,805,060,730 sites and 6,798,101 web-facing computers, reflecting a gain of 4.49 million sites and 84,800 computers. This is the largest number of web-facing computers in history, and cloud computing has helped fuel this growth considerably. The top three cloud hosting providers—Amazon, Alibaba and DigitalOcean—now account for nearly 22% of all web-facing computers, as well as more than a third of this month's net computer growth.

nginx has dominated this month's computer growth once again, with an additional 49,900 computers taking its market share up to 22.2%. This puts it within 20,000 computers of Microsoft's 22.5% share, giving nginx a realistic chance of taking second place by next month. Meanwhile, Apache remains far ahead in the lead with 2.88 million web-facing computers giving it a 42.3% share of the market.

While more than half of the websites in the survey are using Microsoft web server software, relatively few of these are active sites. Discounting link farms, domain holding pages and other automatically generated content, Microsoft accounts for only 7.3% of all active sites, while Apache leads with 44.9%, and nginx follows with 20.7%. Microsoft's active sites share has never exceeded Apache's, and ever since it peaked at 38% in early 2009, it has experienced a general decline.

Microsoft's presence within the top million websites has also been steadily declining – in 2008, it had a 20% share, but this has since dwindled to less than 10%. Today, 9.73% of the top million sites use Microsoft web server software (mostly IIS – Internet Information Services), while Apache leads with 38.9%. However, Apache has also been experiencing a general decline since 2011, while nginx has continued to muscle its way in. A further 1,299 nginx-powered sites made their way into the top million this month, lifting nginx's share to 29.4%.

Web-facing operating systems

Apache has been the most commonly installed web server for many years, but which underlying operating systems are used by the world's web facing computers?

By far the most commonly used operating system is Linux, which runs on more than two-thirds of all web-facing computers. This month alone, the number of Linux computers increased by more than 91,000; and again, this strong growth can largely be attributed to cloud hosting providers, where Linux-based instances are typically the cheapest and most commonly available.

It is difficult to distinguish different Linux distributions by examining their TCP/IP characteristics, but inferences can be made from other clues, such as Server headers. The Linux distribution can be positively identified in around 30% of cases, and of these 1.39 million Linux computers, just over half are running Ubuntu Linux, nearly a quarter are running CentOS, and around fifth are running Debian Linux.

Microsoft is next up, with 26.8% of all web-facing computers running various versions of Windows Server. Interestingly, this is higher than Microsoft's web server share (22.5%), and can be explained by around 20% of Windows computers being used to run other web server software – such as Apache and nginx – rather than its native Microsoft IIS web server. Conversely, around 51,000 Linux computers expose Microsoft IIS web servers to the internet – in these cases, the Linux frontends are typically acting as load balancers or reverse proxies to backend Windows computers running IIS.

Windows Server 2008 is the most commonly used version of the Windows Server family of operating systems – it currently runs on 971,000 web-facing computers, and this is followed by Windows Server 2012, which is installed on 505,000.

Windows and Linux are essentially the "big two" when it comes to web-facing operating systems. FreeBSD was once notorious for its reliability and impressively large uptimes when used as a server platform; indeed, Netcraft's infrastructure made extensive use of it in the past, but it is now a relatively niche operating system compared with its heyday. Today it is used by only 1.3% of web-facing computers, more than half of which are being used to run the Apache web server.