Frequently asked questions

About ownCloud

What is ownCloud and why would I use it?

ownCloud is a file server that enables secure storage, collaboration and sharing.

It is convenient to store files in the cloud, so they are available on any device and can be shared with a few clicks. There are a lot of popular providers like Google, Apple, Facebook, Twitter and Dropbox. With a lot of these vendors, files are stored and processed beyond users control. With U.S. firms, files are subject to the Cloud Act and thus to government snooping.

Consistently based on open standards and modularity, ownCloud is suitable as a robust and security-oriented file platform for proprietary environments and as well open-source software environments. As a result, ownCloud combines fully sovereign file storage with modern, efficient productivity tools while maintaining auditable source code and comprehensive release functions. Users can install ownCloud themselves or rent a managed instance.

You want to use ownCloud to benefit from the conveniences of the public clouds while being compliant and in control of your data.

How secure is ownCloud?
  • ownCloud protects your data using state-of-the-art cryptographic measures in transit, at rest and optionally end-to-end.
  • ownCloud is an open source project so all code is visible. We are committed to building secure code, work following the leading industry security practices and perform regular security audits on the code. Our bug bounty program on hackerone rewards white hat hackers for responsible disclosure of vulnerabilities.
  • To learn more, see
What Service Provider and Partner Programs does ownCloud offer?
  • Service Providers: Please read about our Service Provider programs, branding and options for ownCloud Service Provider Edition. For consideration as an ownCloud Service Provider you need to submit your business plan.
  • Solution Partners are actively serving our joint customers and are the ideal first contact for any customer in the respective country. They are experts in implementation and can help with a variety of underlying infrastructure needs.
  • ownCloud Technology Partners help us to reach customers with innovative joint solutions and joint go-to-market offerings.

Browse an overview of all ownCloud Partners.

Please apply here to become an official ownCloud Partner.

What kind of customers does ownCloud GmbH have?

ownCloud works with several large enterprises across different industries like financial services, energy and healthcare as well as with organizations in science, education and government. Some of our marquis customers include CERN, Daimler, the European Commission, ETH Zürich, Jefferson National and the Dutch Ministry of Defense. Quite a few of our important customers cannot be named for confidentiality purposes. Check out our success stories from customers we actually can talk about.

What is the difference between ownCloud and Nextcloud?

ownCloud is an enterprise-grade open-source file access platform focused on scale and security. Nextcloud is a 2016 fork of the old ownCloud code base that still uses PHP and seems laser-focused on implementing lots of features for small businesses and home users.

What are the benefits of ownCloud being open-source software?

Being open source means you can audit the code to make sure it does what you want. It also means that ownCloud is more flexible and adaptable than closed source software – you can more easily write extensions and even modify the core. Transparency enables peer review which tends to lead to efficient code, good performance and low running costs.

What is the difference between ownCloud Community, Enterprise and Online?

The community edition can be deployed everywhere free of charge and without support even on a raspberry pi. The enterprise edition is the business on-premises solution for everyone with their own data-center. While the online version is especially for SMBs without data center and sys admins. 

Who is it for?

ownCloud is for anybody seeking digital sovereignty and a powerful file access platform, whether they be individuals, small businesses, organizations and institutions large and small, multinational corporations or governments. 

Product & Features

Is it possible to brand ownCloud with my Corporate Design?

Yes, ownCloud offers theming with ownBrander as part of the Enterprise or Custom Subscription. It includes thr Mobile Apps, Desktop Apps and the Web Interface.

How do the ownCloud Apps work?

There are three kinds of apps that you can use to extend ownCloud. There are free Marketplace Apps, Enterprise Apps that are part of the Enterprise Edition and third-party apps. The Enterprise Apps and are fully supported with a paid subscription. Third-party apps are not supported by ownCloud.

What is Federated Cloud Sharing?

The Federated Cloud Sharing Feature enables users to quickly and easily share files with users of other ownCloud instances. Users simply enter a Federated Cloud ID, e.g. instead of a local username to share a file or folder with the other party, who can then edit the file. Federation is particularly helpful for collaboration across organizations, be they companies, universities or public institutions.

Where can I find ownCloud apps?

You can find apps that extend the functionality of ownCloud on the ownCloud Marketplace. To see which Apps you have already installed in your ownCloud, visit [your-ownCloud-domain]/settings/admin?sectionid=apps

Can I use ownCloud in professional, large scale deployments?

Absolutely. ownCloud Server is built for and used in large scale, professional deployments in enterprises, education, research institutions and government agencies. Our customer list includes CERN, SwissLife, Daimler TSS, the European Commission and ZF.

Where can I get an overview of all features?

Please visit our Features page. We’ve compiled a number of needs that ownCloud addresses, please have a look to learn more.

Can I use ownCloud as a backup solution?

No.  ownCloud is absolutely not a backup solution.

  • Changes you make in one place are synchronized to other places which means that if you accidentally remove or overwrite a file on your local system, ownCloud will remove it from the server.
  • If a file gets corrupted at one place the corrupted file gets distributed to other places.
  • The ‘previous files’ and ‘undelete’ functionality of ownCloud is merely meant as a convenience and should never be relied upon as a backup function. Algorithms are in place that clean up ‘old files’ and thus, changes will get lost over time.
  • External Storage connects ownCloud to an external storage like FTP, SMB another ownCloud Server or third-party providers like Google Drive, Amazon S3 or Dropbox. Files will show up in your web interface and can be synced with the client. However, they are not replicated on your ownCloud server!

You should use a backup application to store the files in ownCloud somewhere. The ownCloud documentation has tips on how to back up ownCloud.

What’s the difference between ownCloud Standard Edition and ownCloud Enterprise Edition?

Both include support. The ownCloud Standard Edition ownCloud Enterprise Edition adds a range of Enterprise Apps specifically developed for the needs of corporate clients and large-scale installations. It integrates with SharePoint, Windows network drives, Amazon S3 and more. It also includes support, branding and mobile apps.

For a full feature comparison, please visit

Which solution is best for me?
We don’t know yet. If in doubt, contact us. Chances are that if your organization has more than 50 users, you might want to look into our Enterprise Edition, whether on-premises, as a managed cloud solution or as a hybrid. With lessthen 50 users, you might like, our Software-as-a-Service offering that is ready to rock in minutes. If you like to administrate things yourself, can do without the Enterprise Apps and don’t need support, just install ownCloud Server.
Is ownCloud Server limited to a certain number of users or files and do I have to purchase something to get a ‘full’ version?

ownCloud is open-source software without artificial limitations on things like the number of users or files. You only need a subscription to access to our world-class support desk and to our Enterprise Apps.

Is owncloud free?

It can be, depending on your needs. ownCloud is open source and anybody can deploy it. To unlock additional functionality and support, the ownCloud GmbH offers premium subscriptions.

For which deployment scenarios is ownCloud suitable?
ownCloud fits a number of needs and scenarios.

We’ve compiled a number of needs that ownCloud addresses, please have a look to learn more.

You might also want to peek into our customer list here – it includes key players in education, finance, logistics, research, manufacturing, energy, government and raw materials. Our customer list includes, among others, CERN, SwissLife, Daimler TSS, the European Commission and ZF.

Guides & Docs

Do you have customer references you can share?

Look into our customer list here – it includes key players in education, finance, logistics, research, manufacturing, energy, government and raw materials. Among others, CERN, SwissLife, Daimler TSS, the European Commission and ZF use ownCloud for secure and efficient file access and collaboration. We are happy to provide you with further relevant customer references upon request.

Can I put ownCloud all on one server?

Yes. If you want to scale ownCloud beyond a handful of users however, and are looking for the best performance, you want to consider a more complex setup. To learn more, read our deployment considerations.

What are the Minimum System Requirements to run ownCloud?
Read the current minimum system requirements here.

In short: 512 MB Ram and current versions of a common 64-bit linux distro, apache, php and suitable database.

Note: ownCloud currently does not run on Windows Servers.

Where do I find information on how to use/install ownCloud Server?

You can install with docker, manually or with an appliance

I want to upgrade my ownCloud installation to the new release, how do I do that?

If you installed ownCloud using you Linux distro’s package manager, read how to upgrade here:

If you want to upgrade an appliance install, here are the instructions

For all other cases, check out the manual upgrade guide

Is it safe to upgrade to the new release?
All code entering ownCloud has been reviewed twice as well as tested by both automated means and through the efforts of volunteers. Releases are done only when all issues we are aware of are fixed or can be mitigated easily. In short, ownCloud releases are always as stable as we could make it without your help. If you want the guarantee that it will work in your specific situation, please help test before a release is made so that issues can be fixed in time.

Why should you be testing?

In short: because ownCloud is yours. ownCloud is an Open Source product, following an open development model. That means that many different stakeholders, both commercial and private, contribute to its development and share responsibility for the final release.

Why does the calendar/contacts app not work with Android?

iOS has native ical/caldav support, Android does not. You have to use an Android app that does but unfortunately almost all apps we’re aware of that support caldav/ical are paid. One open source client is DavX5. You can find a list of 3rd-party apps that work with ownCloud here.

Why does the Android/iOS mobile app not support my favorite feature?

If you’d like to add features to the Android or iOS client, find the Android sources here and the iOS sources here. Legal notes: the Android app is under the GPLv2, the iOS app under the GPLv3. To contribute to either, you have to sign a contributor agreement or contribute your code under the MIT license. For testing, we provide a iOS license exception so you can run the iOS app on up to 100 devices.

Why do I sometimes get conflict files and messages while syncing?

A conflict may be caused by two or more users editing the same files at the same time or while on the road before the files are synced. We do not merge changes to files like version control systems like git do; we don’t modify user files, ever. So you will get two files, the one that was synced to the server first and the one you had locally modified in the same time. You can compare the file changes by hand and delete the local file once you’re sure you did not lose data.

Since ownCloud 10.5, you can manually lock files in the Web App.

Technology & Development 

Does ownCloud offer a Proof of Concept?
Yes. Please read about launching a customized Proof of Concept with ownCloud here
What Encryption methods are used and what data is encrypted?

ownCloud encrypts data on three levels: In transit, at rest and optionally end-to-end. With its modular and flexible encryption architecture, ownCloud enables custom setups for every threat level and regulatory requirement.

How does the virus scanner app work?

It scans files on upload to avoid infections with viruses, trojans, and other malicious code using an integration with ClamAV. You may also integrate other virus scanners.

If I have my ownCloud server hosted, does that still help me protect my privacy?

Yes, it does. Encryption in-transfer and at-rest strenghtens data security in hosted environments. Moreover, you get to choose where and with whom you host your data – so you can find a jurisdiction that protects you better or host your data at a provider you trust.

Why does ownCloud use csync rather than rsync?

rsync is a one-way syncing protocol. This means that if you have two servers and delete a file on one side, it will pop up again if you use rsync. To ensure old files get removed but new files added, and updated files overwritten, you need a N-to-N sync solution. ownCloud uses csync for syncing, which also deals with conflicts in a smart way.

Why is ownCloud Server written in PHP?

We picked PHP a decade ago because it lowers the barrier for using, auditing, modifying and contributing to ownCloud

    • Even the cheapest hosting provider supports PHP
    • PHP is easy to learn which makes it easy for people to contribute. The ease of PHP also allows you to check the code that runs your ownCloud and make changes that you need.

Sadly, PHP also has some disadvantages. That is why we are building something new.

Why do you use HTTP and not another protocol?

HTTP goes through every firewall and proxy.

Does the long list of security advisories mean ownCloud is less secure than other solutions?
Rather the opposite. It signals that ownCloud is a mature project taking responsibility for its security.

  • Many large corporations with high security requirements use ownCloud, from finance to defence, subjecting the software to independent security audits. As an open-source project, ownCloud also benefits from a large numbers of eyes looking at its code.
  • We are highly committed to comprehensive yet responsible disclosure of security issues, which is why we publish all potential security relevant issues with a CVE (Common Vulnerabilities and Exposures) system, an international standard in security and availability. With CVE, system administrators can easily see whether their infrastructure is vulnerable or not.
  • No other open-source file access platform is scrutinized like ownCloud. While a lower or higher number of CVE’s does not directly say anything about security by itself, issuing CVE’s is a responsible vendor security practice.
Are files encrypted during sync?

Yes, we use TLS for sending and receiving files over the network so they are encrypted during transmission.

Does ownCloud support file encryption on the server?
Does ownCloud do file de-duplication?

No, as we think that is a job for the file system. ownCloud does maintain versions of files as they are replaced and you may revert to older versions at any time.

Why is ownCloud syncing not faster?

The design of ownCloud is constrained by two important features: scalability and reliability.

  • ownCloud is designed to be very scalable, and be independent of the used storage system. We want it to work with petabytes of data and tens of thousands of users – and it does, organizations like CERN in Switzerland and big universities and University Networks run ownCloud with such amounts of data and users.
  • A second design goal of ownCloud is reliability. We would rather be slower to ensure no files are lost than playing fast-and-loose with user data. For example, the file-change-notifications on Linux and Windows are not 100% reliable in all cases, so just-to-be-sure we run a full file system scan periodically. Yes, that eats battery life, but it does ensure you do not lose any of your files!

This does not mean there is no room for improvement, we work very hard to make ownCloud faster and every release introduces many performance improvements. Also, help is always welcome. Check out the client code on github if you are interested in the challenges of fast, scalable and reliable file syncing! See the contribute pages for more information about getting involved.

Does ownCloud scale to large deployments?

Yes. ownCloud runs on a Raspberry Pi and also powers the Digilocker, the government document cloud in India with more than 200 million registered users.

Contribute & Legal

Where is the ownCloud community hosted?

The ownCloud code can be found at

How can I get involved with the ownCloud Community and be a part of the open-source development?

Yes, find all the necessary information at The development happens at


How big is the ownCloud Community?

ownCloud has an over 200 million users and 398 programmers contribute code in 20 teams. Tens of thousands participate on our forums, mailing lists, translation and documentation tools.

Where can I discuss ideas with other ownCloud users?
If you have a feature request or proposal which you can support with code, check out our contribute page. You can put feature requests in the issue tracker but please be aware that in open source projects like ownCloud, the constraint is rarely ideas or awareness of what can be improved but rather time to work on them.
How can I get involved in the ownCloud Community?
The best way to get started is to visit
I am not very technical can I get involved in the community?

There are lots of ways you can contribute to ownCloud, even non-technical ones. Have a look at!

How can I get started writing mobile (Android, iOS) clients or third party (web) apps?
  • First of all, awesome you want to bring ownCloud support to your app or build an app entirely for ownCloud, rocking!
  • If you’re interested in writing an Android or iOS app with ownCloud support, you can use our MIT licensed libraries on those platforms. Find them on Github: iOS, Android. You can then use the iOS and Android developer docs.
  • To build a third party application accessing ownCloud data through its external API, find the documentation here.
Can I modify ownCloud and run it on my website for others to use/access?

ownCloud Server is available under the AGPLv3. In laymen terms (this is NOT legal advice!) the AGPL license grants you the right to run the ownCloud code wherever and however you want, make modifications and additions and share these with anybody you like. The only limitation is that if you give others access to your ownCloud (by giving them a user account or sharing files with them), you must also give them access to the source code; and the whole source (including your modifications) has to be under the AGPLv3 license.

How to comply

If you have made no modifications to the ownCloud code, the easiest way to comply with the AGPL is to have a small link to and note that users can find the code there.

Otherwise, if you have made modifications, contributing these to ownCloud is sufficient from our point of view. If you don’t want or can’t do that, you have to provide a way for users to download the modifications you made to ownCloud, including the modifications. Providing, upon request, a tarball, zip file or github repository is enough. Make sure they contain the copyright notice; the code has to be under the AGPLv3 or a compatible license like the MIT license.

Some examples:

  • ownCloud apps (ownCloud apps like the calendar or music app from, as you would write following the App Developer documentation, using the public but internal API) are considered an integral part of ownCloud; writing an ownCloud app is thus considered modifying ownCloud and your ownCloud apps are subject to the requirements of the AGPLv3. The ownCloud Enterprise Edition provides an exception as it is available under a proprietary license.
  • External apps like mobile or desktop clients, or apps running on another server and otherwise not part of ownCloud but using the external ownCloud OCS API as you would find here are NOT subject to the AGPLv3 and can be under any license you like.
  • Artwork is not subject to the AGPLv3: you can have a branded ownCloud installation, with modified logo, colors etcetera. You do NOT have to release your logo or other artwork under the AGPLv3.
  • If you use ownCloud yourself (as private user or company!) and do not give third parties access to its user interface or API’s (like webDAV), the AGPLv3 sharing clause does not come into effect. In general, note that you are only ever obliged to share the original source upon request with a third party who has been given access to your ownCloud instance. You must merely make sure that users are aware of this right.
Can I write closed source or proprietary apps for ownCloud Server?
  • Yes, but following the requirements of the under the AGPLv3, these can be distributed or made available to users outside of your household or organization only under the ownCloud Enterprise Edition, which supports integration with proprietary technologies. Contact us for details.
  • External apps like mobile or desktop clients (like those using the iOS or Android ownCloud libraries, which are MIT licensed) or apps running on another server and otherwise not part of ownCloud but using the external ownCloud OCS API as you would find here are NOT subject to the AGPLv3 and can be under any license you like.

I want to report a copyright infringement or other legal matter on a site that mentions use of ownCloud.

ownCloud is an open-source project that can be easily hosted by any person allowing anybody to securely exchange files. Neither the ownCloud open source project nor ownCloud GmbH exert any legal or technical control over those domains. If you found a copyright infringement on a domain other than or, please try to contact the domain owner. ownCloud has no insight or control over ownCloud instances.

Can I use the ownCloud logo on my website, for my ownCloud app or client, or promotional materials?
In short, we want to support you in promoting, using and building on ownCloud but we also want to prevent confusion about the meaning of our logo and trademark and your use of it. The use of the ownCloud trademark is governed by our trademark policy. Carefully read it before you use ownCloud marks (like our logo or our name) on a website, app, flyer or anywhere else.
How do the community and company work together?
The company makes it possible for developers to work full time on ownCloud, organizing ownCloud events, marketing ownCloud to a wider audience and supporting companies, governments and schools in their ownCloud deployments.