Garbage-y scripts affecting response or animation. If you need DOM access, use requestAnimationFrame. Move pure computational work to Web Workers.
The DOMContentLoaded event stalls as it is swamped with JS work.
Long-running JavaScript affecting response. Optimize JavaScript runtime: use requestAnimationFrame, spread DOM manipulation over frames, use Web Workers. User scrolls right after page load, setTimeout / setInterval. See Expensive Input Handlers in Paul Lewis' runtime performance checklist.īadly-timed JavaScript affecting response, animation, load. Let the browser handle touch and scrolls, or bind the listener as late as possible. ProblemĮxpensive input handlers affecting response or animation. The following table describes some common JavaScript problems and potential solutions.
#ELEMENT 3D V2 SPEED UP RENDER HOW TO#
Learn how to create CPU profiles in Speed up JavaScript runtime. CPU profiles show where runtime is spent within the functions of your page. If you notice quite a bit of jank (interruptions of rendering) in your JavaScript, you may need to take your analysis to the next level and collect a JavaScript CPU profile. Take a recording in the Performance tool and look for suspiciously long Evaluate Script events. Do not let badly-timed or long-running JavaScript interfere with user interactions. JavaScript calculations, especially ones that trigger extensive visual changes, may stall application performance. Painting may take up more time than any other rendering activity.Choose CSS that does not trigger layout at all. Use less CSS and keep your CSS selectors simple. Separate read and write functions, and perform reads first. Do not write JavaScript that forces the browser to recalculate layout.Learn about tools and strategies to identify and fix common problems that slow down runtime performance. Each stage in the pixel pipeline represents an opportunity to introduce jank (interruptions of rendering). Users expects interactive and smooth pages.