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I am looking for the best way to replace or add to elements of an array without deleting the origin… Read more Javascript: Is There A Better Way To Retain Your Array But Efficiently Concat Or Replace Items?

Background: So I need to sort lots of strings. Arrays of strings, actually, but that's besides… Read more Difference In Performance Between Calling .localecompare On String Objects And Constructing A Purpose-made Intl.collator Object?

I use a big picture(33440 x 440) and transform the big image, then achieve a animation like as fram… Read more Why Hardware-accelerated Css Animation Cost Too Much "composite Layer" Times In Main Thread?

I've played with jsperf.com and found that prototyped function is 40x slower than 'default&… Read more Why Is Prototype Function 40x Slower Than The Default Declared Function?

I have a very general low level question about dragging. I am specifically interested in learning w… Read more How Frequently Is D3 Drag Event Triggered?

A ajax code that i am using to request a page is consuming too much memory and is making the browse… Read more Ajax Too Slow - Recursion

var name = function(n) { var digits = ['one','two','three','four… Read more Javascript Performance With Closure

I found that there are many frameworks will check the duplicate class name before adding the new cl… Read more Use Duplicate Class Name On An Element?

I have this piece of Javascript code, which takes about 600 ms on every call in Internet Explorer. … Read more Why Is This Piece Of Javascript Code So Slow?

Just asked my first question and got a great response. So helpful. Helped me create this bit of jav… Read more Faster Javascript Processing

The following document mentions some guidelines for performant scaling of HTML5 Canvas: https://dev… Read more Is Canvas Scaling More Performant Via Css Or Js?

Well having grown up in C++, I am always conscious about what algorithm would fit what. So when I n… Read more Why Is Array.includes An Order Of Magnitude Faster Than Set.has In Javascript?

Given this article: http://richardartoul.github.io/jekyll/update/2015/04/26/hidden-classes.html If … Read more Hidden Classes And Equivalence Between {} Object Vs. Custom Constructor (v8)

Find length of line 300* slower First of I have read the answer to Why is my WebAssembly function s… Read more Why Is Webassembly Function Almost 300 Time Slower Than Same Js Function

In response to my answer yesterday about rotating an Image, Jamund told me to use .data() instead o… Read more Save Object States In .data Or Attr - Performance Vs Css?

I have a fairly large multi-page javascript applications that uses requirejs to organize code. I am… Read more Sharing Common Code Across Pages With Browserify

I'm wondering if it is more efficient to place any vars referenced within a loop, outside of th… Read more Do Local Variables Inside Of A Loop Get Garbage Collected?

I'm starting to play around with Boomerang for measuring performance. It's very promising. … Read more Read Size Of Current Document From Javascript

Is there any way to slow down the responsiveness of the client (browser)? One of our testers can re… Read more How To Emulate A Slow Client (browser)?

Does anyone know if there's any benefit in 'minifying' locally-stored javascript code t… Read more Javascript Performance And Minification