Ziproxy vs Janus vs PageSpeed Module - comparison of compression proxies

Only 27% of the global population has access to a fast internet (over 10 Mbps) and hundreds of millions of people around the world have a limited Internet connection. This is where a data compression proxy (a.k.a. web accelerator) comes to the rescue. It optimizes loading of web pages by minimizing HTML/CSS/JS, enabling gzip compression, re-encoding images, etc.

Some time ago I was comparing proxies in the cloud: Mozilla Janus, Opera Turbo and Google Compression Proxy. Now I am testing open source HTTP forwarding proxies: Ziproxy, Mozilla Janus and Google PageSpeed Module (mod_pagespeed) for Apache with mod_proxy, all installed on my premise. This time the primary factor is not loading time, but total size of various web pages.

	Ziproxy	Janus	PageSpeed	Direct
ZDNet	1026 KB	1117 KB	802 KB	1225 KB
TheNextWeb	3768 KB	3638 KB	3672 KB	4156 KB
New Yorker	4528 KB	4872 KB	4782 KB	5357 KB
AntyWeb	1258 KB	2750 KB	1928 KB	3493 KB
iStockPhoto	2905 KB	3699 KB	3444 KB	3756 KB
Total	13485 KB (25% saved)	16076 KB (11% saved)	14628 KB (19% saved)	17987 KB

The best compressing HTTP proxy is Ziproxy with 25% of data savings. The second place goes to Google PageSpeed with 19%. Mozilla Janus was the worst with only 11% saved.

All the proxies were tested with equal image quality settings (60%).

Chrome Data Compression Proxy vs Mozilla Janus vs Opera Turbo

Most of web browser vendors provide a way to speed up browsing by using compression proxy. Opera has long been known for its Turbo/Off-road mode, Google Chrome has the Data Compression Proxy and Mozilla has recently introduced the Janus Proxy, which you can access system-wide using a PAC file at http://janus.allizom.org.

I have tested onload event times of various web pages using all three compression proxies and a direct 5 Mb/s connection over WiFi on my PC. Total times as well as Numion YourSpeed results are shown below:

	Chrome DCP	Mozilla Janus	Opera Turbo	Direct
ZDNet	11.5 s	24.5 s	11.4 s	11.1 s
CNN	14.3 s	20.0 s	12.2 s	10.7 s
BBC	7.3 s	27.3 s	11.7 s	6.6 s
NYtimes	6.5 s	10.7 s	6.1 s	5.6 s
eBay	8.7 s	14.5 s	7.8 s	8.1 s
Amazon	5.3 s	10.6 s	3 s	5 s
Pinterest	7.4 s	12 s	9.2 s	7.3 s
Wikipedia	3.8 s	6.3 s	3 s	3 s
Total	64.8 s	125.9 s	64.4 s	57.4 s
Numion YourSpeed	218 kb/s	119 kb/s	216 kb/s	308 kb/s

Surprisingly, the fastest is a direct Internet connection, but this would depend on your local bandwidth. Opera Turbo and Chrome Compression Proxy go head to head, both using WebP image format. The slowest is Janus, using MozJPEG instead.