Mustafa Yaylak
Co-founder · Managing Director, Operations & Customers
AURUM GmbH’s managing director, Mustafa leads customer relationships and is your contact for demos, pilots and commercial questions.
Mustafa Yaylak on LinkedInOn-premises WOPI client for SharePoint Server SE
The Office Online Server replacement for SharePoint Server Subscription Edition
View Word, Excel and PowerPoint files in SharePoint SE again, on your own servers, after Office Online Server support ends on 31 Dec 2026.
Runs on-premises · no cloud connection · by Aurum Consulting, Microsoft Partner
Why now
Office Online Server support ends. SharePoint Server SE does not.
OOS support ends 31 Dec 2026
Microsoft lists 31 December 2026 as the final day of support for Office Online Server.
Source: Office Online Server lifecycle
SharePoint SE has a separate lifecycle
It follows Microsoft's Modern Lifecycle Policy. Each public update is supported for one year from release, so farms must stay current.
The retirement applies to Office Online Server
Microsoft lists SharePoint Server Subscription Edition separately and does not give it a fixed product end date.
Source: SharePoint Server SE lifecycle
Without a WOPI client, documents in SharePoint SE no longer open in the browser: users need desktop Office, and previews in libraries and search disappear.
How it works
Drop-in replacement for the OOS binding
Your documents never leave your network.
- 1
Install on Windows Server
MSI installer, ready for air-gapped networks. No internet connection required.
- 2
Point SharePoint at it
Run New-SPWOPIBinding, the same step you know from Office Online Server.
- 3
Users click documents as before
Word, Excel, PowerPoint and PDF files open in the browser again. Nothing to train.
Your company network
- Users in the browser
- SharePoint Server SE farm
- WOPI
- Office Render Engine
No connection to the internet or any cloud service
New-SPWOPIBinding -ServerName ore.contoso.local
Set-SPWOPIZone -Zone "internal-https"Product in action
Real documents, rendered on your server
- Pagination matches the original, so page references hold
- Legacy .doc files open the same way as .docx
- Missing fonts are replaced by metric-compatible ones and reported
- Workbooks shown as faithful, read-only previews
- .xls, .xlsx and .xlsm; macros are never executed
- Not an interactive grid yet: no filtering or formula bar
- Every slide rendered as authored, in the browser
- .ppt, .pptx and .pptm supported
- Animations and transitions are shown flattened
- Plain PDFs are served byte for byte, untouched
- PDFs with scripts or attachments are rebuilt from their pages first
- Hover previews in SharePoint search results
Proof
Fidelity you can check, speed you can measure
We compare every release against Office Online Server on a fixed test corpus. The numbers below are published only once they are reproducible.
9 Office formats + PDF · How we test rendering fidelity →
Security & operations
Built for networks that stay closed
On-premises only
Runs on your Windows Server. No telemetry, no phone-home.
Macros never run
Macros are never executed and remote links are blocked.
WOPI proof keys
Every request from SharePoint is validated with proof-key signatures.
Isolated renderer
The rendering process runs isolated, on loopback, with mTLS.
Air-gap ready
Offline installer for networks without internet access.
Operable
Health endpoints and a support bundle for your monitoring and our support.
Honest scope
What it does today, and what comes next
Now
- View Word, Excel, PowerPoint and PDF, including legacy formats
- Hover previews in SharePoint search
- Font substitution reporting
Next
- Document editing in the browser: in development, no release date yet
Early customers become design partners and help decide what we build next.
Read the known limitations →From €0.50 per user per month
24/7 support in English and German · free 30-day pilot
The team
Built by SharePoint engineers
Built by SharePoint engineers at Aurum Consulting, Microsoft Partner from Nürnberg & Zürich.
Hakan Aksuman
Co-founder · Lead Engineer, Rendering & Platform
Hakan leads engineering for the rendering engine and platform, with a focus on how documents are rendered in SharePoint Server SE.
Hakan Aksuman on LinkedInSergej Schwabauer
Co-founder · Lead Engineer, SharePoint & WOPI Integration
Sergej leads the SharePoint and WOPI integration, connecting the rendering service to customers’ on-premises SharePoint farms.
Sergej Schwabauer on LinkedInFAQ
Questions IT teams ask first
Does Office Render Engine support editing?
Not yet. Today it views Word, Excel, PowerPoint and PDF documents. Editing in the browser is in development, without a release date; early customers help shape it as design partners.
Which SharePoint versions are supported?
SharePoint Server Subscription Edition is the supported target. Ask us about SharePoint Server 2019 or 2016. We check each farm during the pilot.
Does any data leave our network?
No. Office Render Engine runs on your own Windows Server, fetches documents from SharePoint over WOPI and renders them locally. It has no telemetry and no cloud connection.
Can it run alongside Office Online Server during migration?
Yes. You can test it on a separate farm or zone and switch the WOPI binding when you are ready. Switching back is the same one-line binding change.
What are the server requirements?
One Windows Server 2022 machine that your SharePoint farm and your users reach over HTTPS. Our starting point is 8 vCPUs, 16 GB RAM and at least 20 GB of local SSD for the preview cache. We confirm the sizing with you for your number of users and document mix before the pilot.
How long does installation take?
Typically under an hour: run the installer, add the certificate, run New-SPWOPIBinding. We help during the pilot.
How are fonts handled?
Fonts installed on the server are used as-is. Missing fonts are replaced by metric-compatible substitutes (for example Carlito for Calibri), so line breaks and page counts still match. Each substitution is reported, so administrators can install the originals.
Which open-source components does it use?
Documents are rendered by a pinned, hardened build of LibreOffice (MPL-2.0). We keep its licence notices and publish any changes we make to its source. A full SBOM is available on request.
Is support available in German?
Yes. Support is available 24/7 in English and German via Microsoft Teams, phone and email.
What happens after the pilot?
The free 30-day pilot converts into a subscription without reinstalling. The subscription starts on the order date.