2019

Web Almanac

HTTP Archive’s annual
state of the web report

Our mission is to combine the raw stats and trends of the HTTP Archive with the expertise of the web community. The Web Almanac is a comprehensive report on the state of the web, backed by real data and trusted web experts. The 2019 edition is comprised of 20 chapters spanning aspects of page content, user experience, publishing, and distribution.

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Featured Chapter

Caching

Caching is a technique that enables the reuse of previously downloaded content. It provides a significant performance benefit by avoiding costly network requests and it also helps scale an application by reducing the traffic to a website’s origin infrastructure. There’s an old saying, “the fastest request is the one that you don’t have to make” and caching is one of the key ways to avoid having to make requests.

27%

Responses not using any caching headers

39%

Responses using the Vary header

82%

Sites that could save 1 MB by optimizing caching better

Read the Caching chapter

Contributors

The Web Almanac has been made possible by the hard work of the web community. 103 people have volunteered countless hours in the planning, research, writing and production phases of the 2019 Web Almanac.

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Methodology

Websites Tested

5.8M

Data Processed

20.9 TB

Unless otherwise noted, the metrics in all of the 20 chapters of the 2019 Web Almanac are sourced from the HTTP Archive dataset. HTTP Archive is a community-run project that has been tracking how the web is built since 2010. Using WebPageTest and Lighthouse under the hood, metadata about nearly 6 million websites are tested monthly and included in a public BigQuery database for analysis. The July 2019 dataset was used as the basis for the 2019 Web Almanac’s metrics. For more information, see the Methodology page.

Learn about our Methodology