#ProTips

The best #WebPerf tips from the top Web Performance Professionals.


“whatsmydns.net lets you check DNS propagation and monitor your changes as they propagate throughout the world.”

   Source:  http://www.speedawarenessmonth.com/the-dns-propagation-waiting-game/


“@photomatt: One of the things that matters to user experience on the web is how quickly users are able to find what they are looking for.”

   Source:  http://www.speedawarenessmonth.com/breaking-down-why-page-speed-matters/


“@bluesmoon – Boomerang: a JS library that measures the page load time experienced by real users.”

   Source:  https://github.com/lognormal/boomerang


“@bebraw: View how Public CDNs perform relative to each other with CDNPerf”

   Source:  http://www.speedawarenessmonth.com/cdnperf-understand-how-cdns-perform/


“@nexcess: BJ Lazy Load is the most popular JQuery-based lazy load plugin for WordPress”

   Source:  http://www.speedawarenessmonth.com/wordpress-performance-four-simple-steps-for-a-faster-site/


“Gzipping files typically results in file size reductions of about 70%. – via @nexcess”

   Source:  http://www.speedawarenessmonth.com/wordpress-performance-four-simple-steps-for-a-faster-site/


“Reducing the TTFB is an important part of a site’s conversion rate optimization strategy. – @dnsmadeeasy”

   Source:  http://www.speedawarenessmonth.com/slow-dns-can-throw-a-spanner-in-your-conversion-rate-optimization-strategy/


“80% of site outages are caused by a failure on the back-end. – @azhawkes”

   Source:  http://www.speedawarenessmonth.com/when-8020-becomes-2080/


“AT&T has a free tool called ARO that analyzes the traffic from your app on your mobile device. – @dougsillars”

   Source:  http://www.speedawarenessmonth.com/mobile-application-performance-caching/


“Don’t just think of a performance issue technically. Include the whole context for the end-user population. – @mtomlins”

   Source:  http://www.speedawarenessmonth.com/dont-cry-wolf-know-your-performance-contexts/


“Convert your 24-bit PNG files to 8-bit easily with 8bitalpha.com – @patmeenan”

   Source:  http://www.webpagetest.org/


“You can use PageSpeed Insights for Chrome to view/export images that need to be optimized. – @jdorfman”

   Source:  http://www.speedawarenessmonth.com/3-ways-to-save-money-on-your-bandwidth-bill/


“Sometimes good measurements go bad. It’s a good idea to re-test them periodically. – @Archivd”

   Source:  http://www.speedawarenessmonth.com/sample-data-like-a-pro/


“In a webpage there are multiple components that determine availability, speed and integrity. – @mdaoudi”

   Source:  http://www.speedawarenessmonth.com/monitoring-101-peeling-the-web-performance-onion/


“In 2006, the average online shopper expected a web page to load in 4 seconds. Today, that same shopper expects 2 seconds or less. – @forrester”

   Source:  http://www.webperformancetoday.com/2010/06/15/everything-you-wanted-to-know-about-web-performance/


“To get a ground-zero look at your site’s performance, capture videos and filmstrip views of your pages’ load times. – @joshuabixby”

   Source:  http://www.webperformancetoday.com/2012/02/13/non-geeky-guide-to-performance-measurement/


“Rely on a global infrastructure that covers your clients needs (self built or CDN) – @mdaoudi”

   Source:  http://blog.catchpoint.com/2012/06/26/10-golden-rules-for-3rd-party-providers/


“Minify is a PHP5 app that combines multiple CSS/JS files, removes whitespace and more: http://j.mp/OLNM8P – @jdorfman”

   Source:  http://code.google.com/p/minify/


“Enable progressive rendering & achieve greater download parallelization: move JS from the top to the bottom… – @souders”

   Source:  http://developer.yahoo.com/blogs/ydn/posts/2007/07/high_performanc_5/


“With Lossy compression image quality is preserved as is with only unnecessary meta-data removed, it often saves up to 30-40% of file size. – @sergeyche”

   Source:  http://calendar.perfplanet.com/2011/lossy-image-compression/


“Histograms are the best way to graph data (not averages). – @JoshuaBixby”

   Source:  http://calendar.perfplanet.com/2011/good-company/


“RUM is becoming our measurement baseline and the ultimate source of truth. – @JoshuaBixby”

   Source:  http://calendar.perfplanet.com/2011/good-company/


“SSL is great but it’s not free. Don’t use it if you don’t have to (use a protocol relative URL). – @zoompf”

   Source:  http://calendar.perfplanet.com/2011/advice-on-trusting-advice/


“Lazy Loading downside: The code isn’t guaranteed to be delivered, the connection can become unavailable in the meantime. – @tobie”

   Source:  http://calendar.perfplanet.com/2011/lazy-evaluation-of-commonjs-modules/


“The SPDY protocol allows web sites to be transmitted more efficiently to the web browser, improvements of as much as 55%. – @bryanmcquade”

   Source:  http://calendar.perfplanet.com/2011/introducing-mod_spdy-a-spdy-module-for-the-apache-http-server/


“Continue testing your website, but make sure to test on mobile devices. Emulators are not simulators. – @estellevw”

   Source:  http://calendar.perfplanet.com/2011/mobile-ui-performance-considerations/


“Mobile users have terrible latency, so a site optimized for mobile should really reduce the number of HTTP requests it makes. – @bluesmoon”

   Source:  http://calendar.perfplanet.com/2011/mobile-ui-performance-considerations/


“Keep your web application files at use at any one time (JS, CSS, HTML and images currently displayed) to under 80MB. – @estellevw”

   Source:  http://calendar.perfplanet.com/2011/mobile-ui-performance-considerations/


“Response times should not be more than eight to 10 seconds (in most cases). – @apodelko”

   Source:  http://calendar.perfplanet.com/2011/how-response-times-impact-business/


“Users feel they are interacting freely with the information (1-5 second Response Time) – @apodelko”

   Source:  http://calendar.perfplanet.com/2011/how-response-times-impact-business/


“Users view 0.1-0.2 second response time as instantaneous – @apodelko”

   Source:  http://calendar.perfplanet.com/2011/how-response-times-impact-business/


“Everyone should have some form of real user monitoring in their performance tool box with the Navigation Timing API. – @bbrewer”

   Source:  http://calendar.perfplanet.com/2011/a-practical-guide-to-the-navigation-timing-api/


“Something unexpected and hidden from the view of many people optimizing web performance are automated bots. – @eastdakota”

   Source:  http://calendar.perfplanet.com/2011/using-intelligent-caching-to-avoid-the-bot-performance-tax/


“Use this bookmarklet to get timing information for any page you are interested in: http://bit.ly/R8Wf8v – @aloisreitbauer”

   Source:  http://calendar.perfplanet.com/2011/timing-the-web/


“Make good use of the network by leveraging parallelization and asynchronous downloads. – @shunra”

   Source:  http://calendar.perfplanet.com/2011/secrets-of-high-performance-native-mobile-applications/


“Our research shows that even on mobile networks you can obtain a performance gain using up to four parallel downloads – @shunra”

   Source:  http://calendar.perfplanet.com/2011/secrets-of-high-performance-native-mobile-applications/


“Yslow allows users to add CDNs to a custom list (one-click-add-cdn) when applicable. – Betty Tso”

   Source:  http://calendar.perfplanet.com/2011/all-aboout-yslow/


“YSlow can also be used as a framework to build extensions that talk to browser, refer to @stoyanstefanov article for code samples: http://bit.ly/R8QTdx – Betty Tso”

   Source:  http://calendar.perfplanet.com/2011/all-aboout-yslow/


“Apply domain sharding to increase the denominator of (N * RTT / 6) by a small constant factor. – @brianpane”

   Source:  http://calendar.perfplanet.com/2011/the-need-for-parallelism-in-http/


“If images happen to be gradients or rounded corners, use CSS3 features to eliminate the need for those images altogether. – @brianpane”

   Source:  http://calendar.perfplanet.com/2011/the-need-for-parallelism-in-http/


“Sprite the images. – @brianpane”

   Source:  http://calendar.perfplanet.com/2011/the-need-for-parallelism-in-http/


“Website owners should use async snippets and patterns, monitor real user page load times, and look beyond averages to 95th percentiles and standard deviations. – @souders”

   Source:  http://www.stevesouders.com/blog/2012/03/28/frontend-spof-in-beijing/


“Make things smaller, move them closer, cache them longer and load them more intelligently. – @joshfraser”

   Source:  http://calendar.perfplanet.com/2011/automating-website-performance/


“Javascript downloads block the loading of other page components that’s why it’s critical to load script files in a non blocking asynchronous fashion. – @stoyanstefanov”

   Source:  http://calendar.perfplanet.com/2011/the-art-and-craft-of-the-async-snippet/


“Anything that isn’t critical for the above-the-fold-page you should not be inlined. – @guypod”

   Source:  http://calendar.perfplanet.com/2011/why-inlining-everything-is-not-the-answer/


“Page images (i.e. images referenced from the page, not CSS) should rarely be inlined. – @guypod”

   Source:  http://calendar.perfplanet.com/2011/why-inlining-everything-is-not-the-answer/


“Very small files (under 4kb) should be inlined. – @guypod”

   Source:  http://calendar.perfplanet.com/2011/why-inlining-everything-is-not-the-answer/