Optimizing page load time

The average size of a web page has been growing at an accelerating rate over the last few years. Last week, when the open-event webapp was tested, it was very slow to load because of loading 67.2 MB data ( which contained audio and image files ) on the web page.I have taken following steps which are good to read to make any web application load faster.

1. Stop preloading of audio files

The HTML5 audio player loads all audio files by default on the page. To stop this we have to change the code as

<audio controls preload="none">
 <source src="{{audio}}" type="audio/mpeg">
 </audio>

Setting preload option to none help us to load audio only when it is clicked. Hence it decreases the HTTP calls and decreases the page loading time.

Previously

Network tab with Audio files takes 68.0MB  load and 13.6 minute loading time.

fail

Now

29

Network tab with option <audio controls preloaded=”none”> takes 1.1 MB load and  1 minute loading time. This was a huge improvement but more optimizations can be done.

2. Using Compression Middleware

Express compression middleware works like a charm by compressing the response coming to the web page. It is too simple to add.

$ npm install compression
var compression = require('compression')
var express = require('express')

var app = express()

// compress all requests
app.use(compression())

// add all routes

This has compressed the responses and decreased the page load time.

3.  Reduce the number of HTTP requests

Another great way of speeding up your web pages is to simply reduce the number of files that need to be loaded.

Combine files

Combining multiple stylesheets into one file is a really useful way of eliminating extra HTTP requests. This strategy can also be adopted for your JavaScript files. A single larger CSS or JavaScript file will often load quicker because more time can be spent downloading the data rather than establishing multiple connections to a server.

After such optimizations, the webapp loads now in 8-15 seconds with DOM loaded in 2 seconds.

fulloptimize

The result of these optimizations are awesome. We can test the page speed by using various tools like pagespeed, speedtracer etc.

Using compression middleware in Node/Express

If you’re using ExpressJS to host your server, there’s a small performance tweak that you can do (works on universally on any kind of server – HTML templates to JSON REST APIs to image servers) – which is to enable GZIP compression.

The changed required to do it should be very simple. First install the compression npm package

 npm install --save compression

In you app.js (or wherever you start your express server), modify the code to include the compression middleware like this

var express = require('express);
var app = express();

var compression = require('compression');

app.use(compression());

// Rest of your app code
// app.get (endpoint, callback) 
// app.listen(port, callback)

This should easily reduce page loads time to the order of 15-20%.

For example, page load before compression middleware added 72f7abf2-4899-11e6-9cd5-68a7addaf3a6

 

And Page load time after compression is added69e6fba8-4899-11e6-9626-a25c26ea7d2b