In the April 2018 survey we received responses from 1,783,239,123 sites across 214,513,048 unique domain names and 7,387,066 web-facing computers. This reflects a gain of 12.8 million sites and 53,500 computers, but a loss of 261,000 domains.

Microsoft dominated this month's hostname growth, with 25.1 million additional hostnames bringing its leading market share up by 1.15 percentage points to 36.9%. Meanwhile, Apache lost 8.2 million sites and nginx lost 5.7 million.

Microsoft fared less well in most other metrics, however. Despite its large increase in hostnames, Microsoft's domain count fell by 1.4 million, and it also suffered a loss of 5,360 web-facing computers and 51,300 active sites. Nonetheless, its presence within the top million sites grew by 517 sites.

nginx may have lost 5.7 million hostnames, but it showed the strongest growth in some of the most important metrics. This included a gain of 46,700 web-facing computers, 3.8 million domains, and an additional 4,280 sites in the top million. The noticeable uptick in nginx-powered domains this month has increased its market share of domains by 1.81 percentage points to 22.5%, leaving it only 3.5 points behind Microsoft. nginx has demonstrated fairly consistent domain growth since this metric was introduced in 2009, and if these trends continue, it could feasibly take second place from Microsoft within a year.

Apache suffered losses in every metric this month, including a loss of 3.0 million domains and 1.1 million active sites, along with 2,840 sites within the top million. Nonetheless, it maintains a comfortable lead in every metric except hostnames, where its 25.6% market share is 11.4 points behind Microsoft's.

Some of the highest-traffic sites using Apache today include news website www.bbc.com; financial sites like www.xe.com and www.paypal.com; the Steam online gaming store at store.steampowered.com and its community forum at steamcommunity.com; and sites used by ad networks, like ads.pubmatic.com and c.betrad.com.

Apache Tomcat – the hidden backend

More than 450 million websites are currently using the Apache HTTP server, but this is not the only web server product offered by the Apache Software Foundation. The Apache Tomcat project provides an open source implementation of Java Servlet and JSP technologies, but its deployment is hard to quantify.

Tomcat is often used as a backend application server, with the Apache Tomcat Connectors project connecting it to other web-facing servers like Apache and Microsoft IIS. In many of these cases, Tomcat cannot be detected passively, although it may be possible to confirm its use during a web application security test – for example, by tricking the application into returning a Java stack trace.

Tomcat also includes its own native HTTP connector that allows it to be used as a standalone HTTP server, and these servers can be passively identified from their "Apache Tomcat" server headers. However, this is not a commonly used configuration: Only 10,300 websites exhibited the Apache Tomcat server header this month, and only 35 of these sites were ranked within the top million.

Several different versions of Apache Tomcat are available, depending which version of Java needs to be supported. Surprisingly, most Tomcat servers that are exposed directly to the internet are running Apache Tomcat 4.1.x, which has not been supported for several years. Actively maintained versions include 9.x, 8.5.x, 8.0.x and 7.x, although support for 8.0.x will end on 30 June 2018. The most recent versions of Apache Tomcat are 8.5.30 and 9.0.7, which were both released on 7 April.

Other new releases

The mainline branch of nginx has seen three new releases since last month's survey. nginx 1.13.10 was released on 20 March 2018, and added a few new features including the ngx_http_grpc_module module, which allows requests to be passed to a gRPC server. nginx 1.13.11 was subsequently released on 3 April, followed by nginx 1.13.12 on 10 April. These releases include a few bug fixes and an improved proxy protocol feature.

nginx also announced the release of njs 0.2.0 on 3 April. njs implements a subset of the JavaScript language, allowing location and variable handlers to be used in nginx's ngx_http_js_module and ngx_stream_js_module modules.

OpenLiteSpeed 1.4.31 (stable) and 1.5.0 RC3 were released on 11 April 2018. This open source server cannot be distinguished from the commercially available LiteSpeed Web Server, as both products use the same "LiteSpeed" server header. More than 12.5 million sites exhibit this header, across 13,600 web-facing computers.

Tengine 1.4.2

Nearly 28 million websites are using Taobao's nginx-based Tengine web server, but 74% are still running a version that was released several years ago, despite later releases including not just new features, but also security fixes. The most extensive user of Tengine 1.4.2 – which was released in November 2012 – is the Chinese cloud computing infrastructure service provider Aiyun Network.

Uptake of new Tengine releases is generally slow across the internet. The latest version, Tengine 2.2.2, was released on 26 January 2018, but only 262 sites are currently using it. Most of these sites are hosted by Internet Vision in Lithuania, while handfuls of other early adopters are hosted on low-cost cloud hosting platforms provided by Aliyun, DigitalOcean and Linode.

The poor uptake of newer releases could be partly caused by their lack of visibility on the Tengine website at tengine.taobao.org. The latest version that can be downloaded from the News section on the homepage is the 2.2.0 development version that was released in December 2016, followed by the 2.1.2 stable version from December 2015. Download links for the much-newer 2.2.1 and 2.2.2 releases can only be found on a separate download page.

cloudflare-nginx still lingers

Cloudflare's migration to its new cloudflare server header is not yet over, with more than 10,000 websites still using the old cloudflare-nginx header. These account for less than 0.07% of all Cloudflare sites in the survey, so the migration is very close to completion.

Cloudflare recently increased the size of its European network to 41 cities, expanding its global network to 151 cities across 74 countries. Its highest data centre is 2.6 km above sea level in the city of Bogotá, Columbia.

In the March 2018 survey we received responses from 1,770,411,187 sites across 214,774,438 unique domain names and 7,333,606 web-facing computers. This reflects a gain of 43,000 computers, and 738,000 additional domains. The total number of hostnames fell by 68.2 million, and the number of active sites fell by 3.4 million.

Domain growth this month was shared between nginx and Microsoft; nginx increased its market share by 0.15 percentage points by gaining 482,000 domains while Microsoft gained slightly fewer with 413,000. Market leader Apache lost 568,000 domains and continues to lose market share, its share now stands at 37.6%.

Apache also loses out when looking at the number of web-facing computers, 31,000 fewer computers were seen running the web server software in March leading to a drop in market share of 0.67 percentage points. Microsoft also lost computers, seeing 100 fewer, while nginx continues to gain both computers and market share. Nearly 1.8 million web-facing computers were seen running nginx in March, giving it 24.5% of the market.

New Releases

The Apache Software Foundation announced the release of Apache 2.4.33 on 23 March; this is the first release announced since Apache 2.4.29 in October 2017, the skipped version numbers were not publicly announced due to issues which came to light during the release process. The 2.4.x branch is recommended over all previous releases.

OpenLiteSpeed, the open source software behind the commercial LiteSpeed HTTP server, received releases to both its stable and latest branches in February, version 1.4.30 was released on 14 February and version 1.5.0 RC2 on 15 February, both releases fix the same set of issues.

lighttpd version 1.4.49 released on 11 March, with it the open source web server adds basic support for the HTTP CONNECT method along with several bug fixes. lighttpd is seen in use serving sites on 500,000 unique domains in the March survey; these are served from 21,000 web-facing computers.

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.