How to calculate approximately the connection speed of a website using JavaScript?

Question

I want to create a javascript widget like, which will calculate the speed opening the current opened page.

I am asking if this can be done using just javascript and what will be the idea.

Update

Note that the page size is always Unknown.

score 11 · Accepted Answer · answered May 20 '09 at 18:01

Here's an example using AJAX with .Net backend, though it could be anything.

Here's a simpler example using an image.

The key is to have a page/object of a known size and capture the start and end times as the browser retrieves it. Then simply divide the size by some [unit of time] to get [size] per [unit of time]. Then use math to translate this into whatever you want.

score -2 · Answer 2 · answered May 20 '09 at 17:57

-2

Sure.

<script>
    startTime = Date.now();
    window.onload = function(){
        endTime = Date.now();
        //Time in ms between opening page, and loading all the date
        alert(endTime - startTime)
    };
</script>

Now to approximate speed. Statically you know let's say page is 200kb.

var kbps = 200 / (endTime - startTime * 1000);

answered May 20 '09 at 17:57

Dmitri Farkov

9,133
1
29
45

and what if i don't know whats the page size in kb, can i get using js as well? – Amr Elgarhy May 20 '09 at 18:05
Javascript has no way of checking file-sizes of pages unfortunately, so I would have to say no. – Dmitri Farkov May 20 '09 at 18:10
3

This will not get you the connection speed. That gives you the load time the page takes to render. – epascarello May 20 '09 at 19:22
so how to get it? there is a smarter way? – Amr Elgarhy May 20 '09 at 19:53
The last line, calculates the average speed with which the page has loaded. – Dmitri Farkov May 20 '09 at 22:02

How to calculate approximately the connection speed of a website using JavaScript?

2 Answers2

Linked