A first look at Opera's Mobile Accelerator

by Edd Dumbill

At least in Europe, data rates for GPRS connectivity are
expensive. Especially if you're paying out of your own pocket!
The costs of even a brief web browsing session on a smartphone can soon
pile up.
A possible solution to this has just been
announced by Opera, in the form of their
Mobile Accelerator.

Mobile Accelerator is a subscription service where you pay for access to
their HTTP proxy. The proxy is smart, and optimizes web content for smartphone
connections in order to reduce bandwidth requirements.

Opera's promotional material says that Mobile Accelerator is “aimed at significantly increasing your browsing speed on mobile devices while also reducing your data traffic costs” and that it “reduces the size of Web pages by approximately 50-70%, but it has the ability to reduce them up to 90%.”

I decided to take the Accelerator for a spin on my Sony Ericsson
P800 phone, running the Opera 6.31 browser. Setting the proxy up was simply
a case of entering the URL of an auto-configuration page. Thereafter
I browsed as normal.

The speed-up you get will depend on the content you read and how much Accelerator can optimize it.
To see if Accelerator lived up to its claims, I performed some experiments.
I tried three different sites: my own weblog, BBC News and O'Reilly Network.
The latter has adverts on it, which introduces some unknowns into my measurements.

I tested the amount of kilobytes my phone had to send and receive over GPRS in order to load each page. I am charged by total data transfer, so the sum of these is the key figure. I didn't test download times, as there were too many variables involved to get an objective measure.

Here are the download results.

Site Normal (KB) Accelerated (KB) Improvement
My weblog 8 + 52 = 60 8 + 32 = 40 33%
BBC News 59 + 135 = 194 26 + 36 = 62 68%
O'Reilly Network 27 + 135 = 162 34 + 92 = 126 22%

Note that the cache was cleaned and Opera restarted before every load.

So it looks like I'm getting savings in bandwidth between around 20% and
70%. At the top end, this is definitely consistent with Opera's claim of 70%.
At the lower end, however, it looks like Opera's 50% figure is a little

The savings afforded by the Accelerator definitely improve when used in
conjunction with your browser's cache. I performed the experiment again for my weblog, but without cleaning the cache:

Site Normal (KB) Accelerated (KB) Improvement
My weblog 8 + 36 = 44 7 + 14 = 21 52%

Of course, when browsing on my P800, I don't always start either with
no cache, or a full cache. Neither do I always have image loading on, as
I did for this test. It certainly is the case that I save bandwidth by
using Accelerator, whatever the conditions.

I did notice that there was some visual change to pages from going
through the proxy. For some sites, the body font appeared to get larger
when using Accelerator, and some whitespace opened up between table elements.
However, I saw nothing that seriously limited the readability of a page.
In fact, using Accelerator rendered one page readable where previously the
text had been squeezed into a 20 pixel wide column.

For my normal browsing use, this visual alteration is irrelevant however,
as I use Opera's “Fit to screen” mode, which does an excellent
job of rearranging a page's content to fit well into the P800's available

So, crunch point. Will Mobile Accelerator pay for itself? I often use a
lot of GPRS data, but more often through fetching my email over a Bluetooth
link to my laptop. Accelerator only works with web content, obviously, so how
much do I need to browse to make a saving? Opera are offering the service at 3
Euros per month. Given that I might expect to get around 50% data saving, this
means the break-even point is 6 or more Euros worth of GPRS in web browsing.

Given my current Vodafone price plan, 6 Euros will buy me just over 0.5MB of
access. It seems like Opera Accelerator would be a sensible purchase.
Hopefully in the long term it will drive down data prices, as network operators
realise people are paying Opera money in order to pay less to the

Does this product make sense to you?
Are there any open source alternatives?