Office Online Server delivers browser-based versions of Office apps in an on-premises environment, giving users more flexibility and collaboration opportunities. Office Online Server is the next version of Office Web Apps Server and it delivers browser-based versions of Word, PowerPoint, Excel, and OneNote to be more specific.
It works with products and services that support WOPI (Web app Open Platform Interface protocol). These products, known as hosts, include SharePoint Server, and Exchange Server etc. Kindly refer to this interesting guide: How to Install Apache OpenOffice on Ubuntu, Why should you use Veeam to protect your Microsoft 365 Data?, How to integrate Mendeley Cite for Microsoft Word on Mac and M365 Backup: Why is it imperative to protect Microsoft 365?.
Office Online Server is a component of Office; therefore, it will be shown under each of the Office product pages including Office Standard 2016, Office Professional Plus 2016, and Office 2016 for Mac Standard. Here are some related guides: How to Cancel Office 365 Family Subscription, How to install and activate Office 2019 on your Mac PC, How do you change the account that Office says it belongs to on a Mac, and how to Fix Microsoft Excel Crash Issue
A single Office Online Server farm can support users who access Office files through SharePoint Server, Exchange Server, shared folders, and websites. Therefore, if you wish to run OOS, it can be downloaded from the Volume Licensing Service Center (VLSC): For customers whose licenses qualify for OOS, but cannot obtain it through the VLSC, the following actions are possible:
- VL Open customers can contact their Support Center.
- Customers who purchased O365 online from Microsoft can submit a request from their Office 365 admin center or contact support.
Office Online Server version compatibility list
Note: SharePoint Server 2013 cannot use the Excel Online external data connectivity and data refresh functionality in Office Online Server. This functionality is available starting with SharePoint Server 2016.
The table shows the compatibility between Office Web Apps Server and Office Online Server with SharePoint Server, Exchange Server, and Skype for Business Server.
|Product||Office Web Apps Server||Office Online Server|
|SharePoint Server 2013||Yes||Yes*|
|SharePoint Server 2016||No||Yes|
|SharePoint Server 2019||No||Yes|
|SharePoint Server Subscription Edition||No||Yes|
|Lync Server 2013||Yes||Yes|
|Skype for Business Server 2015||Yes||Yes|
|Skype for Business Server 2019||Yes||Yes|
|Exchange Server 2013||No||No|
|Exchange Server 2016||No||Yes|
|Exchange Server 2019||No||Yes|
With Office Online Server, users can also view Office files that are stored outside SharePoint Server, such as those in shared folders or other websites. This functionality is provided by a feature known as
Online Viewers. With this in mind, we shall be discussing some scenarios such as the following below.
- How SharePoint Server uses Office Online Server for viewing and editing Office documents
- How Exchange Server and Outlook Web App use Office Online Server for previewing Office file attachments
Scenario 1: With SharePoint Server 2016, Office Online Server provides Word Online, Excel Online, PowerPoint Online, and OneNote Online. Users can view and, in some cases, edit Office documents in SharePoint libraries by using a supported web browser on computers and on many mobile devices, such as Windows Phones, iPhones, iPads, and Windows tablets.
Note: That Office Online Server only works with SharePoint web applications that
use claims-based authentication. Below are the viewing and editing capabilities of OOS.
Excel Online includes external data connectivity and data refresh features similar to those found in Excel Services in SharePoint Server 2013. (Excel Services has been removed from SharePoint in SharePoint Server 2016.). Therefore, you should use Excel Online instead.
Scenario 2: OOS works with Exchange Server and Outlook Web App. When Exchange Server is configured to use Office Online Server, users of the Outlook Web App can preview Office file attachments by using Word Online, Excel Online, and PowerPoint Online. These previews provide rich, full-fidelity viewing of Office files and any comments within them, without downloading the files before viewing them.
- By default, the following file types are displayed using Office Online Server:
- Word documents (doc, docx, dotx, dot, dotm extensions)
- Excel documents (xls, xlsx, xlsm, xlm, xlsb extensions)
- PowerPoint documents (ppt, pptx, pps, ppsx, potx, pot, pptm, potm, ppsm extensions)
Note 1: Office Online Server won’t be used to render any attachments in IRM-protected messages.
Note 2: Office Online integration for attachment previews is available to all Exchange Online customers. Exchange on-premises customers have to deploy Office Online Server to enable the functionality.
Planning Office Online Server installation
At a minimum, an Office Online Server topology will include one
physical or virtual machine running Office Online Server, and at least one host (for example, a server running Exchange Server or SharePoint Server etc). And of course, you’ll need a client PC or device to connect to one of the hosts and use the functionality.
Note: From that minimal topology, you can add more hosts and more servers to your Office Online Server farm as required to suit the needs of your organization. For some best practices, kindly take a look at this link.
It’s important to carefully plan so that all hosts, such as SharePoint Server and Exchange Server can communicate with Office Online Server. Office Online Server can be installed on a single-server farm, or a multi-server, load-balanced farm.
The server requires dedicated servers that run no other server applications, however, you can install Office Online Server on virtual machines if needed.
An Office Online Server farm can provide Office services to multiple on-premises hosts, and you can scale out the farm from one server to multiple servers as your organization’s needs grow. The server requirement for OOS is exactly the same as for “Hardware and software requirements for SharePoint Server 2016”. Also for the supported OS, kindly take a look at this link: Plan Office Online Server – Office Online Server. Other requirements are as follows
- All servers in the Office Online Server farm must be part of a domain. They can be in the same domain (recommended) or in domains that are in the same forest.
- If you plan to use any Excel Online features that utilize external data access (such as Data Models, Power Pivot, or Power View), Office Online Server must reside in the same Active Directory forest as its users as well as any external data sources that you plan to access using Windows-based authentication
OOS Upgrade requirement
Microsoft releases a new build of Office Online Server. Once a new build has been released, critical updates are no longer produced for the previous build. Microsoft recommends that you update your Office Online Server farm as new builds are released. You can determine your current build by looking at the Version number in Add/Remove Programs.
OOS compatibility with other workloads and services
Here are a few things to be aware of when you install Office Online Server.
- Don’t install any other server applications on the server that’s running Office Online Server. This includes Exchange Server, SharePoint Server, Skype for Business Server, and SQL Server. If you have a shortage of servers, consider running Office Online Server in a virtual machine on one of the servers you have.
- Don’t install any services or roles that depend on the Web Server (IIS) role on ports 80, 443, or 809 because Office Online Server periodically removes web applications on these ports.
- Don’t install any version of Office. If it’s already installed, you’ll need to uninstall it before you install Office Online Server.
- Don’t install Office Online Server on a domain controller. It won’t run on a server with Active Directory Domain Services (AD DS).
Office Online Server Firewall requirements
Make sure the following ports aren’t blocked by firewalls on either the server that runs Office Online Server or the load balancer:
- Port 443 for HTTPS traffic
- Port 80 for HTTP traffic
- Port 809 for private traffic between the servers that run Office Online Server (if you’re setting up a multi-server farm)
Planning language packs for Office Online Server
Office Online Server Language Packs enable users to view web-based Office files in multiple languages from SharePoint Server document libraries, Outlook Web App (as attachment previews), and Skype for Business Server (as PowerPoint broadcasts). But, this depends on the languages that are configured on the host. The language packs can be downloaded from this link.
To view web-based Office files from hosts in multiple languages, you must have the following in place:
- The host (such as SharePoint Server or Exchange Server) is configured to run applications in additional languages. The process of installing and configuring language packs on the host is independent of installing a language pack on the Office Online Server farm.
- The languages are installed and are available on all servers in the Office Online Server farm.
Office Online Server communicates with Team Center, Netscaler, SharePoint Server, Skype for Business Server, and Exchange Server by using the HTTPS protocol.
There is a need to install an Internet Server certificate on the OOS.
- In a test environment that contains no production/user data, you can use HTTP for SharePoint Server and Exchange Server and skip the certificate requirement step.
Note: Skype for Business Server supports only HTTPS. Ensure the certificate you are using meets the OOS certificate requirements. Office Online Server doesn’t require any special certificate properties or extensions. For example, Client Enhanced Key Usage (EKU) extensions or Server EKU extensions are not required.
Facts to know about Online Viewer
By default, Online Viewers functionality is enabled after you install Office Online Server. Review the following guidelines if you’re planning to use Online Viewers in your organization. In some cases, you might want to disable some features within Online Viewers.
Files that are intended to be viewed through a web browser by using Online Viewers must not require authentication.
In other words, the files must be available publicly because Online Viewers can't perform authentication when it is retrieving files. It is strongly recommended that the Office Online Server farm that you use for Online Viewers is only able to access either the intranet or the Internet, but not both. This is because Office Online Server doesn’t differentiate between requests for intranet and Internet URLs. Somebody on the Internet could request an intranet URL, for example, causing a security leak if an internal document is viewed.
For the same reason, if you have set up the Office Online Server to connect only to the Internet, it is recommended to disable UNC support in Online Viewers.
Planning Windows Updates for OOS
Before deploying Office Online Server, you need to decide how your organization will manage software updates to your Office Online Server farm. Although software updates help improve server security, performance, and reliability, installing updates incorrectly can cause issues with the Office Online Server.
Applying Office Online Server updates by using the Microsoft automatic updates process isn’t supported with Office Online Server. Updates to an Office Online Server must be applied in a specific way, as described in this link.
If Office Online Server updates are applied automatically, users might be unable to view or edit documents in Office Online. If this happens, you have to rebuild your Office Online Server farm
It is recommended to manage updates by using Windows Server Update Services (WSUS) or by using Microsoft Endpoint Configuration Manager, which uses WSUS. WSUS allows you to fully manage the distribution of updates that are released through Microsoft Update for each server in the Office Online Server farm. By using WSUS, you can decide which updates can be automatically applied to the server farm and which updates, such as Office Online Server updates, have to be manually applied
If you do not use WSUS or Microsoft Endpoint Configuration Manager, please set Microsoft automatic updates on each server in the Office Online Server farm to
Automatically download but notify user for install. When you’re notified of an Office Online Server update, follow the steps in this article “how to apply updates to an “Office Online Server”
Installation of Office Online Server
Deploying Office Online Server involves installing some prerequisite software and running some PowerShell commands, but overall the process is not complicated at all.
Steps to install OOS
1: Install the required roles and services for Windows Server 2016, 2019, and 2022.
Note: if you are installing on a Windows Server 2012 R2, the syntax will be different.
Note: The .NET Framework 4.5.2, the Visual C++ Redistributable Packages for Visual Studio 2013, Visual C++ Redistributable for Visual Studio 2015, and Microsoft.IdentityModel.Extention.dll are not required for Windows 2019.
2: Installing OOS: After the installation of Windows Features, proceed with the installation of OOS. To install OOS mount the download ISO, and execute it. For me, I have it already downloaded.
Next, you will have to click on “Run Setup.exe”
Next, you will have to accept the Accept the User Access Control if implemented in your environment. Here are some UAC related guides: How to Change User Account Type in Windows 10, and how to turn UAC on or off in Windows.
On the Read the Microsoft Software License Terms page, select I accept the terms of this agreement and click Continue.
On the Choose a file location page, select the folder where you want the Office Online Server files to be installed. I am okay with the default, therefore, I will click on Install Now.
Note: If the folder you specified doesn’t exist, Setup creates it for you. But it is recommended to install Office Online Server on the system drive.
As you can see, the installation is in progress. The installation is pretty fast.
When Setup finishes installing Office Online Server, choose Close.
Install language packs for Office Online Server
Office Online Server Language Packs let users view web-based Office files in multiple languages, whether they’re opened from SharePoint document libraries or Outlook on the web. To install the language packs, follow these steps.
Download the Office Online Server Language Packs from the Microsoft Download Center, and run wacserverlanguagepack.exe.
Accept the UAC if implemented in your environment.
In the Office Online Server Language Pack Wizard, on the Read the Microsoft Software License Terms page, select I accept the terms of this agreement and select Continue.
As you can see the Language pack is currently being installed.
When Setup finishes installing Office Online Server, choose Close.
Office Online Server Configuration
Since I am only interested in secure connections (HTTPS) which is also recommended for production environment for its security features. Also, HTTPS is required if you want to provide Office Online Server functionality to Skype for Business Server 2015, which lets users view PowerPoint broadcasts in a browser. Here’s how to install a single-server Office Online Server farm that uses HTTPS. You’ll need to install a certificate on the server.
Note: If you wish to deploy a single Office Online Server Farm that uses HTTP, please take a look at this link.
Certificate request and Bind the SSL Certificate to OOS website:
For a single-server farm, the certificate must be imported directly into the server that runs Office Online Server. Don't bind the certificate manually. The New-OfficeWebAppsFarm cmdlet you run later will do this for you. If you bind the certificate manually, it'll be deleted every time the server restarts.
If your OOS is to be used only within your local intranet, perhaps it is okay local certificate authority or a self-signed cert.
Note 1: Self-signed certificates are not trusted by default and they can be difficult to maintain. Also, they may use outdated hash and cipher suites that may not be strong.
Note 2: For better security, purchase a certificate signed by a well-known certificate authority.
For some reasons, I will not be showing the steps to bound your certificate to the website!
Deploy a single-server Office Online Server farm that uses HTTPS
Import the PowerShell Module: When the OOS installation is complete, there is a need to create a farm by running the following PowerShell Command below. Next, Create the Office Online Server farm by using the New-OfficeWebAppsFarm command to create a new Office Online Server farm that consists of a single server, as shown in the following example.
New-OfficeWebAppsFarm -InternalUrl "https://interntechdarchive.com" -ExternalUrl "https://interntechdarchive.com" -CertificateName "OfficeWebApps Certificate" -EditingEnabled
- InternalURL is the fully qualified domain name (FQDN) of the server that runs Office Online Server, such as
- ExternalURL is the FQDN that can be accessed on the Internet.
- CertificateName is the friendly name of the certificate.
- EditingEnabled is optional and enables editing in Office Online when used with SharePoint Server. This parameter isn’t used by Skype for Business Server 2015 or Exchange Server because those hosts don’t support editing.
As you can see, the operation has been completed successfully.
Verify that the Office Online Server farm was created successfully
After the farm is created, details about the farm are displayed in the Microsoft PowerShell prompt. To verify that Office Online Server is installed and configured correctly, use a web browser to access the Office Online Server discovery URL as shown below. The discovery URL is the InternalUrl parameter you specified when you configured your Office Online Server farm, followed by /hosting/discovery. For example
If Office Online Server works as expected, you should see a Web Application Open Platform Interface Protocol (WOPI)-discovery XML file in your web browser.
The farm is now ready to provide Office Online functionality to hosts over HTTPS.
Now you can start to integrate with Exchange
In the next guide, I will be showing you how to integrate OOS with Exchange Server. I hope you found this blog post helpful. Please let me know in the comment session if you have any questions.