March 19, 2013
Testing change: The default connection speed was increased from DSL (1.5 mbps) to Cable (5.0 mbps).
Oct 1, 2012
Testing change: Instead of stopping the test recording at window.onload, the test is continued until network activity stops. (See the web10 WebPagetest parameter.) One result of this is that the number of requests and total size of pages increased because more network requests were captured.
September 1, 2012: Number of URLs increased to 300K for IE. iPhone increased from 2K to 5K.
June 15, 2012: Want pain? Try loading today’s websites over dial-up
Pingdom quotes HTTP Archive page size stats.
June 4, 2012: Chrome Networking: DNS Prefetch & TCP Preconnect
Ilya Grigorik quotes JavaScripts stats from the HTTP Archive.
May 24, 2012: Bad news for site owners and mobile users: The average web page is now 1 MB
Joshua Bixby from Strangeloop Networks sites statistics from HTTP Archive about growth of web content.
May 1, 2012: Number of URLs increased to 200K for IE.
April 28, 2012: Blocking JavaScript with Web Page Test
Cites growth of JavaScript from HTTP Archive.
April 19, 2012: Another reason why it’s a good thing Flash is going away
Pingdom blog post about the large size of Flash resources. "HTTP Archive, a project that analyzes thousands of web pages each month to get this statistic and more. It’s a great resource, so check it out if you like technical stats about web pages."
April 18, 2012: Unsuitable Image Formats for Websites
Zoompf blog post about less common image formats. "According to the awesome HTTP Archive, the most common image formats on the web are PNG, GIF, and JPEG:".
April 16, 2012: Pages vs. No. Resources
Andy Davies' analysis of data. "Did it to validate the 150 resource default of the proposed W3C Resource Timing spec".
April 1, 2012: Number of URLs increased to 100K for IE.
March 15, 2012: Switch from IE8 to IE9.
January 2012: Migrated to new data center.
November 17, 2011: Added the ability for anyone to add a site to the crawl.
November 1, 2011: # of URLs increased; Page Speed version changed
Several changes occurred affecting the crawl and long term trends:
June 1, 2011: HTTP Archive Mobile grows from top 100 to top 1000 URLs.
May 13, 2011: HTTP Archive Mobile
The "alpha" version of HTTP Archive Mobile is announced at the Mobilism conference in Amsterdam. Initial runs are of the world's top 100 sites.
April 8, 2011: CNET News Flash use dips at top Web sites since November

Article published on CNET News citing various statistics from the HTTP Archive.

April 5, 2011: hide small runs

The first three runs in the HTTP Archive (Oct 5, Oct 22, and Nov 6) only had ~1000 URLs. Comparing those small runs to the later larger runs (that have ~17,000 URLs) can be misleading. (See this blog post.) This change removes those first three runs from the UI to avoid these confusing comparisons. The data is still downloadable.

March 25, 2011: Page Speed updated

We used to run har_to_pagespeed to generate Page Speed scores. With this change the Page Speed scores are generated from WebPagetest. This means that more rules are evaluated and the score is more informative. When using har_to_pagespeed the input is a HAR file so any rules requiring access to the page's DOM can not be scored. WebPagetest, however, generates the Page Speed score while the page's DOM is available, thus resulting in a more accurate evaluate of the page's performance.

One side effect of this change is that comparisons of Page Speed scores to runs performed before March 25 are not apples-to-apples comparisons because this change in which rules are evaluated.