Measuring page load time with Pingdom Tools
Recently, my main “brain dump” blog – Another Day, Another Digression – has been hitting some kind of snag, causing the home page (or rather a portion of the home page) to load very slowly – unacceptably slowly. Thankfully, the content portion of the page loads quickly; it is the right-hand sidebar that takes so long to appear. I am talking long, as in several seconds.
I didn’t have a chance to examine this loading speed issue for several days after noticing it, but I finally got around to measuring the load time with a fantastic free online tool: Pingdom Tools, a free way to get a detailed report showing hundreds of readily measurable variables relating to web page load time, or what geeks call client-server conversation.
Pingdom Tools includes three main tests, all free:
- Full-Page Test
- DNS Health
- Ping and Traceroute
Test the Load Time of a Web Page: Enter a URL to test the load time of that page, analyze it and find bottlenecks
I was not happy to see the initial result: Your website is slower than 84% of all tested websites…
Test #1: Another Day Another Digression (WordPress blog)
Performance grade: 84
Load time: 9.10 s
Page size: 720.9 kb
Your website is slower than 84% of all tested websites
Test #2, same as above
Performance grade: 77
Load time: 6.30 s
Page size: 895.9 kb
Your website is slower than 76% of all tested websites
Compare those to BWN, a static site of mine:
Test #3, BestWeb Nashville (static website)
Performance grade: 79
Load time: 2.06 s
Page size: 337.5 kb
Your website is faster than 70% of all tested websites
Pingdom Tools allows users to download the HAR file, which is the client-server conversation data in HTTP Archive format – a file format similar to XML.
The most direct way for the typical PC user/power user to view and work with HAR files locally is to install the popular Firefox extension Firebug; however, since Firefox quit working on my ultra-finicky desktop PC a couple of days ago, I had to go with something that would work as a Chrome extension, so I installed Firebug Lite. According to some HAR info I was reading, a Firebug extension called NetExport is also necessary.
There’s also HAR Viewer:
HAR Viewer (HTTP Archive Viewer) is an online tool visualizing HTTP Archive (HAR) files produced by HTTP tracking tools. These files contain a log of HTTP client/server conversation and can be used for an additional analysis of e.g. page load performance.
Noted during these load time tests:
• Images really slow things down; 60% of the load time for ADAD was for images
• Apparently the PHP image rotation script takes up some of that image time; it has to choose one at random
• The PayPal link used 12% of the load time; Google Analytics, about 3%, Stats, about 3%
• The CSS file took 4% of the time
The DNS Health Test included a warning about each of the two name servers used for my Bluehost web hosting account:
Name server ns1.bluehost.com (220.127.116.11) is recursive.
The name server answers recursive queries for 3rd parties (such as DNSCheck). By making a recursive query to a name server that provides recursion, an attacker can cause a name server to look up and cache information contained in zones under their control. Thus the victim name server is made to query the attackers malicious name servers, resulting in the victim caching and serving bogus data.
Resources: Measuring webpage load time
- Pingdom Tools
- Load time and WordPress – Any way to make this theme load faster? – BytesForAll user forum
- HAR to Page Speed – Steve Souders
- PCAP Web Performance Analyzer
- WordPress Bible By Aaron Brazell – Google Books
HAR file format (HTTP Archive) resources
- HTTP Archive Specification
- HTTP Archive Viewer 2.0.15
- HarViewer: Visualize HTTP Archive log files – Google Code
- Software is hard: More musings on software development – NetExport
- HAR Viewer – Software is Hard
Tuesday, November 22, 2011