Scripts with the defer attribute are executed in order (i.e., first script one, then script two). This means the script is executed as soon as it is downloaded-without blocking the browser in the meantime-and that the second script can be downloaded and executed before the first script. Scripts with the async attribute are executed asynchronously. Solution - Put scripts in the tag and use the async or defer attributes, which allows the scripts to be downloaded ASAP without blocking your browser. This slows the performance of the page load. Whenever the parser encounters a script, it stops and executes the script before it continues parsing.
Additionally, before the browser can render a page it has to build the DOM tree by parsing the HTML markup. at the top), this may result in loading blocking while the JavaScript files are downloaded. When the HTTP specification puts JavaScript elsewhere on the page (e.g.
Issue - Grouping JavaScript at the end of the page markup is optimal for page load. However, if JavaScript is not placed and executed from an optimal place in the code, not minimized, nor used inline, it may negatively affect the application performance on mobile devices that traditionally have minimal resources. JavaScript is used on many desktop and mobile applications because it extends the functionality of web pages, is a relatively easy language to learn and use, and it executes relatively quickly on the client side. The most common issue found is JavaScript use. Some of these recommendations may occur in the web server layer, which may be separate from the program code. However, we suggest that developers research the capabilities of the system to determine if they can be. Keep in mind, if a website is developed using a content management system (CMS) or development framework, not all of these settings may be configurable. Combine Multiple Files For Improved Performance.Combine CSS Image Assets into Sprite Files.Use External Stylesheets to Separate Caching of CSS from the Content.Avoid Absolute Dimensions and Positions in CSS Directives.The information here outlines the top five practices we found across these sites: For more information on how we conducted the tests, see the Methodology section at the end. Most of these areas do not directly relate to usability issues, but instead, concern how the site is built (which can lead to poor performance). The results indicated that these were the common practices that make these sites not as mobile-friendly as a user might expect or want in a mobile experience. federal government websites that are most visited on mobile devices (smartphones and tablets) using seven mobile-friendly automated test tools. But how can you work on each of these areas to help ensure your website keeps mobile users delighted and coming back?įor six months, from Septemto March 22, 2018, the Federal Crowdsource Mobile Testing Program tested the 26 U.S. These are the top practices that the most visited government websites should focus on in order to be more mobile-friendly. JavaScript usage, CSS usage, image and resource sizing, caching/network usage, and pop-ups. Afterward, close the browser.This guide was created by David Fern, Social Security Administration Navigate to a Java-enabled website to check whether JavaScript works or not. Scroll down, and select Accept Cookies.Ĭlose and reopen the browser. Scroll down the list, and tap Enable JavaScript. In the Privacy and Security section, tap Block Cookies, and select Never or From Third Parties and Advertisers.įor BlackBerry, launch the BlackBerry browser.
Make sure the switch turns to the On position. Tap Advanced, and tap the switch next to JavaScript. You can find the JavaScript option in the Chrome browser under the Content Settings header.įor iOS, tap Safari from the Settings menu. Go to Settings, and tap Privacy and Security. Next, tap Advanced, and select Enable JavaScript.
Wait for the operating system to load.įor Android, open the Android browser. Press the power button on your phone to boot into the home screen.