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A: To make use of external SD card write access on Lollipop and later editions of Androids you have to give FolderSync (version 2.7.1 and later) the necessary permissions. You do this in settings using the External Storage permission option. You will then have to select the SD card and press select. Its important you select the root of the external SD card you want FolderSync to access orit won't work correctly. If you have select a subfolder it may not work as expected.

In regards to writing to external SD card on Android 
It is possible to write to external SD card on Android 4.3 and earlier without issues. It is also possible on Android 5.0 and later using new Storage framework. On Android 4.4 it is not possible (unless for system apps), because of changes made to Android by Google. 

If on Android 5.0 or later
Enable external storage permission by going to settings and pressing "External Storage permission" and follow the instructions. You need to have an external SD card mounted for this to work and this must be detectable by FolderSync. 

If on Android 4.4.x
Best option is to be rooted and applying this fix if on Android 4.4: 

If not rooted, FolderSync can write to these folders in Android 4.4 on a removable external SD card: 
Full - /Android/data/ 
Lite - /Android/data/ 
But be AWARE that files in these folders can be deleted without warning upon un-installation of FolderSync.

Its also important to note, that if you change your SD card, you must regrant permissions for that SD card to FolderSync or the new SD card won't have write access. You must do this everytime you change SD card, no matter if a SD card has been previously granted permissions. If you decided FolderSync should no longer have write access to external SD card, you can revoke its permissions in settings also.

A: FolderSync's current sync engine progresses through the folder structure of the remote and local folders as they sync runs, and process each folder on its own. FolderSync doesn't know how many sub folders and files that may remain to be synced in folders not yet processed. It is perhaps possible to list all files/folders before syncing of changed files starts, but it may still take a long time to calculate this because it can depend on 1000's of web requests for large folder structures, and when no files are synced, this is essentially what happens anyway.
Think about it like this: if you run a sync where no files are transferred, the time that the sync needs to run, is the same time as is needed to calculate the number files to be synced (if there had been any). So it doesn't make sense to show progress for syncs's where no files are transferred (because when the calculation is ready, the sync has completed). A future version of FolderSync may include a updated sync engine, where this calculation is done, and all files are transferred at the end of the sync. Then it will be possible to show how many file transfers remain in sync.

A: Generally modified time stamp for a file is set on download and upload, not at any other time. However not all cloud providers or protocols support setting modified time stamp of uploaded files, so images that is uploaded may get a newer modified time stamp than on the device etc..
This table will illustrate which providers and protocols support setting the modification time stamp for an uploaded file:
Provider/protocol Modification time stamp preserved
Amazon S3 No
Box No
Dropbox No
FTP Yes (if supported by server)
Google Docs No
Google Drive Yes
NetDocuments No
SFTP Yes (if supported by server)
SkyDrive No
SMB/Cifs Yes (if supported by server)
SugarSync No
Ubuntu One No

A: This answer will try to address a range of common reasons why your files may not sync as you thought they would:

If subfolders or some files are not syncing at all - make sure sync of subfolders is enabled. Also check if the files or folders not marked as hidden (in Google Docs this will happen if you choose to hide items from being shown in "home"). If so, enable sync of hidden files. Also make sure items are not excluded because of a sync filter.

Connections - make sure the allowed connection type is enabled at the time the sync should run or else the folderpair will not be synced at all.

FTP/FTPES - if you have problems with FTP syncing, please try the legacy option first before contacting support.

Special characters in file names - please use universal acceptable file characters in file and folder names. Some good recommendations can be found here:
Box doesn't accept file names or folders that start with a dot ".".

A: Unfortunately this feature will not be enabled, since it can cause scheduled syncs not to work and then a lot of users will probably complain. :-) However, if you have a rooted phone you can use this tool to move any app to SD:

Just as long as you know that doing so may cause scheduled syncs not to work correctly.

A: Sadly any problems with the Android Market is outside our control. You will have to ask Google for support.
If you can't download a purchased app, try again a little later, then it usually works. A few users simply can't purchase apps, and they continually get "Internal market error". If you get this error you could try purchasing on
If you think you have accidentally purchased the app twice, then please check the billing statements. One of them will probably say cancelled and that no charge has been performed, so there is no need to contact support for a refund. :-)

A: When syncing a conflict can occur when both the local and the remote file has been modified since the last sync. You then have four options: to skip the file, to use the newest file or to use either the local or the remote file.
A conflict gets detected when both the local and remote modified time stamp for the file has changed since last sync - FolderSync could then of course just use the newest file, but then what if you had made some changes to the "older" file, that you wanted to save?
A conflict will not be detected in cases where the modified time stamp is within the threshold for modified time stamp bug fix setting

A: Transfer speeds can be slow for many reasons and can vary from device to device. FTPS/SFTP speeds can potentially be increased by disabling compression, since this limits how much data can be sent by how fast the CPU can compress the data. The speed of the memory card can also influence transfer speeds of course.
Transfer speeds have been compared to other popular file managers and they are comparable on the devices we test on, but we are aware that users on some device experience lower speeds.

A: There is a bug in Android versions 2.1 and below that means FolderSync cannot connect to the SkyDrive website using SSL, because it uses a certificate with too long a keychain. From version 1.9.2 its possible to work around this issue - on earlier versions FolderSync will crash when you try to create the OAuth token on 2.1 devices.

To use SkyDrive on Android 2.1 devices here is what you must do:
Open the address below in a browser on your PC or other non-2.1 device:

Login with your Windows Live credentials and after that, allow access for FolderSync.

Retrive the code from the address bar in your browser - the value after "code=":[code_is_here]

Enter the code into the username field on the account creation screen for SkyDrive in FolderSync and press validate. If done correctly, save the account and you can now use SkyDrive. If you choose to destroy your access token in FolderSync and save your account, you will have to redo the above procedure the next time you want to log in. Please note: for FolderSync to work with the SkyDrive service on 2.1 devices, SSL checking is disabled.

See more about the Android OS bug here:

A: Microsoft has imposed some limitations on the current API apps can you use to interact with SkyDrive. Read more about it here:

It is not allowed to create an app that automatically uploads files to SkyDrive. That means FolderSync cannot run syncs that up loads files to FolderSync automatically, without the risk of being blocked by Microsoft. That is why syncs will only run if manually initiated. One-way sync to local SD card will run automatically though, as it doesn't upload files.

Photos that are uploaded to SkyDrive through the API are limited to a maximum resolution of 2048 x 2048 pixels. Any photo over that resolution is scaled proportionally to fit within a maximum size of 2048 x 2048 pixels. Photos are now uploaded in the original size as this limitation has been removed.
In addition there is a 100 MB max file size limitation.

A: Create a database backup in the lite version in the settings menu. Then fire up the full version and restore database to import settings - this will overwrite existing settings so beware. That's its.

A: File deletions does get synced. Many complains in comments that they don't but that is probably because it's disabled by default. I have yet to be contacted directly by any that have this problem, and unfortunately I can't respond directly to comments (thanks Google). "Do not sync deletions" has to be disabled for a FolderPair for it to work. So if you experience that this doesn't work, then please send me a log file recording a sync where it doesn't work as expected, so I can fix the bug.
Folder deletions are supported from version 1.9.0 and up.

A: The app has been submitted to the Amazon app store, and can be found here:

A: The aim is, with time, to support as many cloud providers as possible.
Some notes about other providers that have been requested.
  • Wuala:
    Wuala only provides a read-only API for 3rd party developers. It will not be supported before they provide support for writing files to the cloud.

  • Rackspace, Flickr, Minus, Pogoplug, Storegate etc.:
    These will be supported in the future, if API allows for full write access.

A: There is some kind of bug on some Android versions, where timestamps of files change independently of Foldersync, even if they haven't changed. It could be caused by media scanning the SD card, remounting or rebooting or perhaps issues with timezones but we do not know for sure. We don't have the problem on our test devices, and currently only a small subset of users have this problem.
We are looking into handling this issue using md5 checksum to see if local files have changed before they are synced again. Look for it in a future release.
If the timestamp of a remote file change, for whatever reason, even if the file is unchanged, then FolderSync will not be able to detect it and the file may be retransferrred.

A: First of all the full version is required. The full version works as a Tasker plugin - when you configure a new task in Tasker you are presented with a number of Action categories, one of these being "Plugin". Select this and then select "FolderSync" plugin action. Then press edit and select the folderpair you wish to start syncing with this task is executed by Tasker. Then save the task as you normally would in Tasker. For a more general introduction to tasker go here:

A: In the file manager and on the folder selection screen for local files, there should be a drive icon at the top of the screen. Press this to access the root folder. From there any file or folder should be selectable. Accessing file/folders in protected internal memory may cause errors on some devices.

A: There can be many reasons for this. If you have the app installed on SD card, the scheduler will not be set on boot up of the device because of limitations in the Android OS. This is why FolderSync from version 1.7.0 on will have its install location set to "internalOnly". Otherwise it will mean scheduled syncs will not run until you have started FolderSync at least once.
Another reason can be that the connection type is not allowed for the folderpair that is scheduled to sync, or some other condition is not met.
You can also try enabling "Use full wakelock" in settings - some devices require this setting to be enabled or they will not wake correctly.

A: Unfortunately bucket names with periods (.) in them is no longer supported by the Amazon API. This is because it results in SSL certificate errors when the Amazon server is accessed by an url like I recommend the period character is replaced by a dash or other legal domain name character.

A: To setup a LiveDrive or HiDrive account, you select either a SFTP, FTP or WebDAVs account type on the account creation screen. You use your normal LiveDrive/HiDrive username/password and enter them into the corresponding fields.

You then enter the following in the server address field (select the value corresponding to the account type you have selected):
  • SFTP:
  • FTP:
  • WebDAVs:
HiDrive Strato:
  • SFTP:
  • FTP:
  • FTPS:
  • FTPES:
  • WebDAVs:
That's it, you should now be able to validate and save your account.

A: Dropbox recommends in their API specification that mobile applications handle the login process, including sending username/password to Dropbox to get authentication tokens. FolderSync complies 100% with Dropbox official recommendations and does not save the Dropbox passsword after the user has created these authentication tokens on the account screen. So thanks for the 1-star rating for complying with official Dropbox specifications. :-)

However, the new Dropbox beta SDK does support authentication using OAuth, and we will of course support that soon.
Note: From version 1.6.0 on FolderSync support the new OAuth scheme for Dropbox.
Q: I get a "Received message is too long: 1416128878" error when connection to SFTP. Why?
A: This seems to be a problem with the server. It responds with something the FolderSync doesn't understand. See detailed answer below:

When I try to use sftp or scp2, I get a message like this:
Received message too long (or "Bad packet length") 1416586337
and the connection fails. What's wrong?

"In order for this to work, the SSH session must be "clean" — that is, it must have on it only information transmitted by the programs at either end. What often happens, though, is that there are statements in either the system or per-user shell startup files on the server (.bashrc,.profile,/etc/csh.cshrc,.login, etc.) which output text messages on login, intended to be read by humans (likefortune,echo "Hi there!", etc.). Such code should only produce output on interactive logins, when there is a tty attached to standard input. If it does not make this test, it will insert these text messages where they don't belong: in this case, polluting the protocol stream between scp2/sftp and sftp-server. The first four bytes of the text gets interpreted as a 32-bit packet length, which will usually be a wildly large number, provoking the error message above"

So you need to modify the SFTP server in some way, so that it doesn't send back plain text.
Q: FolderSync doesn't delete removed files in a two-way sync. Why?
A: FolderSync has a fairly simple sync engine, meaning that FolderSync doesn't store state for each individual file. Thus the only information it knows about a file is what it knows at the time of the sync. Thus, if you delete a previously synced file for a two-way sync folderpair on either the local or remote end, this file will be resynced, because FolderSync sees this a an unsynced file. This is intentional.

Note: From version 1.4.0 on FolderSync support deletions in two-way sync.
Q: FolderSync uses a rather large amount of memory. Why?
A: This is is something we are hoping to solve very soon, but it has proved tricky. It should have improved somewhat with the latest releases though.
Q: FolderSync overwrite changes in my local/remote file and uses the oldest file. Why?
A: This can only happen if the rule "overwrite always" is used, or if you are experiencing the Android OS bug mentioned in the next question. If "overwrite always" is not set, FolderSync will never overwrite the newest file - but the bug mentioned results in the newest file having an older timestamp. See below for more details.
Q: FolderSync sometimes sync files that haven't changed. Why?
A: FolderSync compares the lastmodified timestamps on the local and the remote file when the option to overwrite older files in a folderpair is set. If the targetfile is older, it is overwritten by the sourcefile. AmazonS3 and Dropbox don't have any support for setting the timestamps of uploaded files, so when a file is uploaded to one of these services, FolderSync attempts to set the timestamp on the local file, to ensure the timestamps are in sync.

Likewise when a file is downloaded, the timestamp of the localfile is set to that of the file in Dropbox or Amazon S3. This ensures, that on the next sync check FolderSync will see the files as identical.

However, on some Android devices there is a bug in the operating system that makes setting the timestamp of the local file fail. Thus, at the next sync check, typcially when using two-way sync, FolderSync sees that the cloud and local file have different timestamps, and thus syncs the file again. This will then happen every time.

From version 1.4.0 on the local and remote timestamp are stored in a database, and used for comparison at next sync. Along with an user configurable option to to ignore a timestamp difference, this should eliminate the resyncing problem.
For information regarding the Android OS bug see these references:

Q: FolderSync syncs over 3G but I told it not to. Why?
A: There was a bug in an earlier version that could cause FolderSync to revert to 3G/mobile if WiFi connection was lost during a sync, and vice versa. This has been corrected, and if connection reverts to a not allowed connection type, the sync will now fail.

Q: I can download the lite version, but I am not able to buy the full version. Why?
A: There can be many reasons for this. Some countries like China are not supported in Android market. Another reason can be that the device is not valid, because it doesn't follow Google guidelines. Note that FolderSync is not restricted from any devices or countries by our doing. There are several steps you can take to try to remedy the situation.

Try using market enabler or similar tools:

For people with MIUI rom (and possible others with custom roms):