Javascript Benchmarking with JSBenchtest

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Javascript benchmarking couldn’t be easier. With this webpage you can input any Javascript code and test how fast it is. The webpage will automatically call your code for 1,000,000 iterations and report the total amount of time that it took to execute. It will even output a variable that you can use for debugging. You can now test an algorithm, make a modification, and test again to see if the modification helped the execution time.

Click here to benchmark some code.


When you visit the page it’ll show you some sample code that you can run. The number of iterations will default to 1,000,000 for all browsers except IE (100,000 for IE). You can change the code to your own algorithm and run the benchmark.

As soon as you press the button, a cookie will be created to store what you entered. At any time you can come back to the webpage and continue your testing with the code that you entered last.

The page includes jQuery 1.7.1, so you can be confident in using jQuery functions. It also includes setCookie and getCookie functions if you wanted to work with cookies. Instead of using the eval() function, which is considered bad practice in Javascript, the webpage sets your code to a new Function object. This improves the speed considerably at runtime.

The Code

//Pads a number to 2 decimal places
function pad2(number) {
	 return (number < 10 ? '0' : '') + number	   

//An output variable that you can use.
var out = "";

//Does the work
function startBenchmark(){
	out = "";
	var SB_iterations;
	var SB_results = document.getElementById("results");
	var SB_code = document.getElementById("code").value;
	//test iterations for incorrect value
	if((SB_iterations = parseInt(document.getElementById("iterations").value,10)) == 'NaN'){
		SB_results.innerHTML = '<span style="color:red;font-weight:bold;">Error: The iterations must be a whole number such as 100000. Do not use commas or words.</span>';
		return false;
	//check for blank code
	if(SB_code == ''){
		SB_results.innerHTML = '<span style="color:red;font-weight:bold;">Error: You must type some code into the text area.</span>';
		return false;
	//too slow
	/*var fn = function() {,SB_code);
	//better method
	var fn = new Function(SB_code);

	var SB_start = (new Date).getTime();
	/* Run a test. */
	for(var SB_i=0; SB_i < SB_iterations; SB_i++){
	var SB_diff = (new Date).getTime() - SB_start;
	var seconds = Math.floor((SB_diff/1000)%60);
	var minutes = Math.floor((SB_diff/(1000*60))%60);
	var ms = SB_diff - (minutes*60*1000) - (seconds*1000);
	SB_results.innerHTML = "<p>Runtime: "+SB_diff+"ms<br />"+
		pad2(minutes)+":"+pad2(seconds)+":"+pad2(ms)+" (mm:ss:ms)</p>"+
		(out != ''?'<p><span class="bold">Output Variable:</span> '+out+'</p>':'');

This entry was posted in Javascript, JQuery and tagged , , , , , by Allan Bogh. Bookmark the permalink.
Allan Bogh

About Allan Bogh

I'm a lead engineer with Disney ID, developing the next generation login website that business entities will incorporate into their websites.

I'm an Active Directory consultant, programmer, web developer, database developer, and tinkerer. I am also the administrator of The Open Code Project. I created and moderate r/ActiveDirectory and, am the primary developer of Reddit Uppers and Downers Enhanced (a part of RES). I also have a love of robotics, working with the Arduino platform.

Sample Projects:


  • Disney Examples to come!
  • ImgAlbum - ImgAlbum is a picture album website that includes speedy image delivery using custom GD2 PHP code and folder/subfolder traversal. Other album websites such as Picasa don't include sub-albums or subfolder uploads, so I am developing my own system where a user can upload an entire folder structure full of images and the system will automatically process the images to create albums.



  • Reddit Uppers and Downers Enhanced - Lead developer, improved speed significantly, incorporated other developers' additions with attribution, project is a part of RES and is used by tens of thousands of people every day.



  • RE/Max Properties website - Created MLS replication system, pulling NWMLS XML records using PHP. Created a Google Maps interface to display NWMLS results on the website (no longer in use). Before leaving I created a home value calculator based on the MLS data and make the website into a template system for agents.



  • Stealth Media Solutions - A website and graphic design company that I used to work for. The website was designed by our designer, I implemented the code with rudimentary means compared to the frameworks available today.



  • Photography Plus - Another design of Stealth Media Solutions. This website includes a WYSIWYG editor for the owner to modify pages. It uses PHP, and Flash.



  • Highpointe Church - Flash PoC. Highpointe Church wanted a proof of concept design from Stealth Media Solutions. Our designer made it and I created the webpage in Flash. The customer was very specific about using Flash, although it may not have been the most flexible choice. Custom javascript was developed to resize the background image dynamically (worked best in Firefox and IE).


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