Do you dread the arrival of your phone bill, terrified that this is the month you've finally gone over your data limit? If so, you should download Onavo immediately (over Wi-Fi, of course) to save your precious megabytes of data. Onavo is an excellent app for reducing data usage on your iPhone. If you're traveling abroad or looking to pare down your plan, it's a must-have and an Editors' Choice.
Device Support, Data Compresson, Setup, and User Interface
Onavo supports devices running iOS 4.0 and above on AT&T, which means you can use it with an iPhone 3GS ($49, 4.5 stars) or iPhone 4 ($199-$299, 4.5 stars), as well as a 3G-based iPad (4.5 stars) or iPad 2 ($629-$729, 4.5 stars). There's no support for the iPhone 4 on Verizon ($199.99-$299.99, 4 stars) right now. A spokesperson for Onavo says this is due to the technical differences between GSM and CDMA devices, and they're working on it.
How Onavo Saves Data
So how does it work, exactly? Everything you do on the Internet is routed through Onavo's servers, compressed, then sent to your device. This is similar to what RIM does with its BlackBerry devices, using server-side compression to reduce the total amount of data you use. The Opera Mini Web browser also uses server-side data compression; the main difference here is that Onavo also compresses email and application data. In my tests, Onavo said only 20 percent of the data I used was in the browser, so that's a lot of data Opera Mini doesn't touch. Similar compression software has been implemented on Windows Mobile devices and Verizon modems in the past, but has mostly fallen by the wayside lately.
Since all of your data is being routed through Onavo's servers, security and scalability are issues. Onavo's system runs on Amazon's EC2 cloud servers. Its servers are protected by multiple layers of security, and nothing is actually stored except for aggregated and anonymized metadata, such as what types of apps you're using—this information is used to help illustrate your data usage and savings, as well as for research to help improve the service. Onavo cannot read or compress encrypted SSL traffic. The only exception is Microsoft Exchange mail traffic, which requires the user's explicit approval.This can be turned off from the app's Settings.
Installation and Interface
To get Onavo, head over to the App Store for a free download. The app is currently free, but some parts may come at a cost in the future. Setup is fast and easy. Onavo installs a configuration profile on your device, which redirects your Web connection through Onavo's proxy. This is explained in the setup process and the whole thing only takes a minute or so.
Using the app couldn't be simpler. Once installed, simply open it up and let it run in the background for instant data compression whenever you're using a 3G connection. The user interface consists of just three menus—Data Saver, Reports, and Settings. Data Saver tells you if the app is running and how much data you are currently saving. Reports breaks down your data usage statistics into helpfully illustrated charts and graphics to let you know how much data you are saving/using and where that data is coming from; you can view these reports on a daily or monthly basis. The Settings menu provides you with a wealth of options, from whether you want to compress email data, to a sliding scale used to choose image compression quality; the lower the quality, the more data you save.
Onavo worked flawlessly throughout my tests. Since Wi-Fi usage doesn't affect your data plan, Onavo automatically switches itself off when you're connected to a Wi-Fi network and switches itself back on when you leave Wi-Fi range.
I tested Onavo on an iPhone 4. I turned every compression setting on, turned Wi-Fi off, and took Onavo for a spin through some Web pages, apps, and maps. At first I left the image compression quality at the default setting, which is Medium. Browsing sites like cnn.com and nytimes.com, I thought I was able to see a slight dip in image quality, but wasn't sure. I took a screen grab, then switched Onavo off, reloaded each page and took some more screenshots. I then repeated this same test using the low and high quality compression settings.
Flipping through the screenshots, you can absolutely see the difference in image quality. On low quality, Web images tend to look blurry and pixelated, though not unrecognizable. They look much better on medium quality, and I was barely able to discern the difference between high quality and turning Onavo off entirely.
Regular text on Web sites is unaffected by the compression, so you never have to worry about a page becoming unreadable. Even when you zoom in, text is every bit as clear as it is with data compression turned off. It should be noted that routing your data through Onavo's servers has an effect on speed, but it isn't drastic. Web pages take longer to load, but only by a few seconds.
Onavo compresses Exchange email; you can also set up your Gmail account as an Exchange server if you want to compress it. If you choose to use email compression, Onavo reformats your emails to plain text—this means that images, bold, underline, and other formatting techniques are replaced with plain text. At the end of these emails you'll see a message that says, "This message has been downloaded as plain text." If you want to see the full, uncompressed email, you can scroll down a bit further and tap on the Download Full Message button.
If you don't want to compress anything, but want to see a breakdown of your regular data usage, you can always switch data compression off.
Data Savings and Conclusions
Over two days of testing, Onavo reported that I saved, on average, about 50 percent on my data usage with the image quality level set to Medium for most of the time. It showed that the majority of data I used was Video/Audio. Onavo doesn't compress streaming video, so save your Netflix and YouTube viewing for a Wi-Fi connection. But 50 percent is still an impressive number. If you regularly use 1GB of data per month, it means you would save 500MB.
For users that travel abroad, where every single megabyte of data costs a premium, Onavo is an essential travel companion. And if you're looking to downgrade your monthly data plan to save money on your monthly bill, Onavo is a great tool to help you monitor your data consumption habits, and in many instances to help you lower them. That makes Onavo worthy of an Editors' Choice from us.
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