Yahoo! Smush.it™ Free Mobile Performance Testing with Akamai's Mobitest. Configuring YSlow / Page Speed | Show Slow. HTTP Archive Viewer 2.0.15. Paste HAR log into the text box below and press the Preview button.Or drop *.har file(s) anywhere on the page (if your browser supports that). HAR Log Examples Inline scripts block - Inline scripts block the page load.
Blocking time - Impact of a limit of max number of parallel connections. Browser cache - Impact of the browser cache on page load (the same page loaded three times). Single page - Single page load (empty cache). HAR Logs Online You can also preview any HAR file (in JSONP format) that is available online by using inputUrl parameter (see more in the About tab): This viewer supports HAR 1.2 (see the About tab).
Wireshark · Go Deep. YUI Compressor. According to Yahoo! 's Exceptional Performance Team, 40% to 60% of Yahoo! 's users have an empty cache experience and about 20% of all page views are done with an empty cache (see this article by Tenni Theurer on the YUIBlog for more information on browser cache usage). This fact outlines the importance of keeping web pages as lightweight as possible. Improving the engineering design of a page or a web application usually yields the biggest savings and that should always be a primary strategy.
With the right design in place, there are many secondary strategies for improving performance such as minification of the code, HTTP compression, using CSS sprites, etc. In terms of code minification, the most widely used tools to minify JavaScript code are Douglas Crockford's JSMIN, the Dojo compressor and Dean Edwards' Packer. Documentation: Detailed description of the YUI Compressor and how to use it. How does the YUI Compressor work?
Using the YUI Compressor from the command line Additional notes. PageSpeed Insights.