What Android device should you buy?

Note: As of SurveyCTO 2.60, released on September 3rd, 2019, SurveyCTO also supports data collection on iOS devices. iOS is brand new to SurveyCTO, and does not have every feature that SurveyCTO Collect on Android has (although we aim to close the gap). See this article for guidance on what iOS supports as compared to Android.

So, you’re thinking about using SurveyCTO for your next data collection project? We think it’s pretty great, but we might be biased. Whatever you decide, there’s a good chance that one of the next decisions you’ll need to make will be what device to purchase. Because Android manufacturers change their lineup of models too often for us to keep track of all of their specifications we can’t recommend specific brands or models, but we are happy to offer you some advice about things to consider while you’re making your decision. What to buy depends on the features that are important to your project and how much future use you plan to get out of your devices. Before we get into details, the single most important bit of advice we can give you is to buy one unit of your chosen device and test it thoroughly before making any larger purchases.


While you can generally rely on the devices made by familiar, well-known manufacturers, don’t discount many of the brands emerging from China which might be less familiar than those popular in the US and Europe but who are releasing some amazing devices that are very good value. Focus on the features you need and specifications the device offers more so than on the name of the manufacturer.

Language and font support

One of the most important considerations is device support for the language and fonts required for your study. This will increasingly become a legacy consideration as manufacturers add support for more languages in new device models. If your study will take place in a country which uses Latin script (including English and most Romance languages), you should have no trouble.

Most importantly, SurveyCTO Collect for Android supports Unicode character encoding. However, Unicode font encoding is not always the default for non-Latin languages, so this can add complications.

A great many non-Latin scripts are also well-supported on most devices (often with Unicode fonts) but it should not be assumed. This depends on the device and region the devices are purchased in (see below for guidance on where to purchase devices).

If you are planning a survey on mobile devices for an audience that speaks a non-Latin language, it is critical that you be sure that your devices can support that language. SurveyCTO Collect for Android has no built-in font support, so it depends on your device.


An on-board GPS chip is really important to have for most projects. Budget devices with only tower-assisted triangulation (sometimes called “a-gps”) are not a good idea, as you won’t be able to get GPS coordinates when 100% offline.  We would argue that a dedicated, onboard GPS chip is a must.

A quick trick to know whether a device has a dedicated GPS chip is to check location settings on the device. If it has a “gps-only” option, then it has an on-board GPS chip.

Cellular functionality

Speaking of connectivity, SIM card support would be a good idea. Wi-Fi-only tablets might be a lot of trouble to sync regularly enough with the server, and generally would require your surveyors, or teams, to have wireless hotspots to connect to. The sooner your data gets uploaded to your server, the better.

Even better, consider devices that can take multiple SIM cards! While uncommon in the U.S. and Europe, such devices are common in other markets. Having SIM cards from different networks installed in your devices can help cope with poor network coverage.

Also, be sure to double-check that the devices you are considering can operate on the frequencies used by mobile network operators in the country that data collection will take place. This is increasingly a legacy concern, as mobile devices can often work on several frequency ranges.


Will your surveyors take photos as part of data collection? Do they need to be good quality? Then consider the built-in camera. Most devices above the cheapest have acceptable cameras these days, but you will want to do some tests beforehand to figure out the best size/quality trade-off for your project.

Storage and memory

When you're shopping for a device, you have to take both storage and memory into account but since SurveyCTO doesn't usually collect large amounts of data (unless you are taking pictures and videos), memory/RAM will have a greater effect on your day-to-day experience. So if you’re looking for a tie-breaker between two similar devices, prioritize RAM over processor speed and storage.

For a budget device, 8-16GB of storage and 2GB of RAM should be considered a bare minimum. In general, go for as much RAM as you can within your budget.  

What is the difference between storage and memory?

People often use the terms RAM, memory, space, and hard drive interchangeably, but all of these phrases actually refer to two separate things. The analogy I like to use when explaining RAM (also called memory) vs storage (also called the hard drive) is to compare your device to a desk. A desk has a tabletop, where you can open books and look at them, and drawers, where you store things you are not using at the moment. If a desk has a lot of drawers but a small desktop, you can have lots of books and files in your drawers but you can only look at a few of them on your desk at a time. Open too many and you’ll have to close some or stack them on top of each other, which becomes inefficient when you’re trying to read more than one at a time. On the other hand, with a spacious desktop, you can open a lot of books and files at once and glance between them easily and quickly.

So, memory, or RAM, is like the size of the desktop. This determines how much information you can have open at one time on your device and not experience slowdowns. Storage, or the hard drive is like the number of drawers you have. The more drawers you have, the more books and files you can store inside your desk.


The most important consideration with device screens is their clarity and readability under different light conditions. A screen that appears perfectly clear and usable inside your office might be unclear in direct sunlight, making it very hard to work with in the field. This is an important reason to test devices in real world conditions before buying in bulk. Problems with visibility might however be managed with the right protective screen cover or case for the device.

Overall screen quality and higher resolutions are nice to have but are probably things you might choose to compromise on in favour of price. If displaying videos or images in your survey is important, better quality screens might be worth the investment.

Screens will also be variably durable and the newer a device, the more likely it will have a better grade of damage-resistant glass covering the screen.

Battery life

Battery life is really important BUT you can compensate with power banks to charge devices and keep them going in the field. If you have the budget for it, get a power bank per tablet, at least. Also think about how you’ll charge all your tablets and power banks in-country. Keep in mind that GPS and cellular functionality are big drains on the battery, so depending on your use case it could be helpful to train your surveyors to put their device in airplane mode unless they are actively transmitting data. If you have a dedicated GPS chip (as we discussed above) it will still turn on when necessary even if the tablet is in airplane mode.

Android version

While you can collect data on Android using SurveyCTO Collect on any version of Android that is 2.3 or later, versions of Android before 3.0 severely limited the amount of memory an application has access to. This could limit the length and complexity of the forms your device could run smoothly. Security bugs and other bugs are continually being fixed, and later versions of Android introduce features that could be useful for your project. So, there are many reasons to use a recent version of Android.

Significantly, if you are running Android 4.2 or older, you will be restricted to using a legacy version of SurveyCTO Collect for Android (download v2.41 here) that supports older versions of Android. While Android 4.3+ will support the latest version of SurveyCTO Collect for Android, we recommend devices running Android 5.0+ at this stage as some devices prior to 5.0 have some compatibility problems. The very latest version of SurveyCTO Collect uses modern standards for communicating with the operating system and other apps (e.g. the camera app) which can be a problem for devices in the gap between 4.3 and 5.0.

Keep in mind that some vendors refer to Android versions by their number, and some by their nicknames. This Wikipedia article has a useful chart matching the nicknames to version numbers, so you can use it as a reference while shopping. Also keep in mind that it is possible to update your tablets after receiving them, but this depends on the manufacturer (support for later versions varies by model and manufacturer), and if you are in an area with unreliable internet updating could be a very laborious process. Ideally, aim to get the latest version preinstalled that you can. Note that while updating the Android operating system is a good idea, you don't want your devices to do this automatically in the field, over mobile internet, as this will use up a lot of mobile data, possibly leaving your enumerators without service.

Where to buy

Where you buy your devices from might be largely governed by the best price. However, take vendor relationships and past reliability into account. Paying a little more per device might be worth it if the vendor offers a better warranty and is someone who has been trustworthy in the past. Be careful not to buy devices which are locked to a given mobile network.

Also, consider purchasing devices in the country they will be used. While it could be expedient to purchase devices in your own country, set them up and then travel with them, this has disadvantages too. Firstly, travelling with a large amount of mobile devices will mean problems with customs -  you may find yourself liable for customs duties for importing consumer electronics. Further, contemporary air travel regulation is restrictive as to the number of and size of the lithium ion batteries you can carry with you. Buying devices locally also means that you’ll be more likely to receive chargers with the devices that work in domestic wall sockets, which will save you buying adaptors.

It is not impossible to put a number of devices in check-in luggage, or to ship devices by international air freight, it is just better to not have to organize such things as emergency measures. You’ll want to be confident that devices you’ve bought at home and have carefully setup, arrive in one piece on the other side. If you do plan to purchase your devices in another country have them shipped, give yourself plenty of time and build in a few weeks to your estimate to account for potential delays with local customs officials.

Test one before you buy in bulk

Lastly, to reiterate, the most important advice we could give is that you should ideally buy a sample tablet and test it carefully before buying more. This won’t be possible in all cases but one can avoid a lot of trouble down the line with this approach.

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