Known limitations & roadmap
What Office Render Engine does not do yet, stated plainly, so there are no surprises in week two of a pilot.
Not in this release
- No editing: view only. No co-authoring.
- Excel is not interactive: no scrolling grid, filtering or formula bar.
- PowerPoint animations and transitions are shown flattened.
- Macros, ActiveX and OLE embeds are neither executed nor rendered.
- No Visio, OneNote or Project files.
Environment
- Fonts. Fonts installed on the server are used. Missing ones are replaced by metric-compatible substitutes (Carlito for Calibri, Caladea for Cambria), and every substitution is reported for
.docx,.xlsxand.pptx. For legacy formats the same substitutes are used, but the substitution cannot be reported. - Authentication. Each authentication context is approved only after a recorded live test. Unvalidated setups are checked with you before a pilot.
- Password-protected documents cannot be previewed.
- Very large documents (above 300 MB source, 50 MB or 5,000 pages of output) are offered as a download instead. Limits are configurable.
- Capacity. Rendering runs on a fixed number of workers (four by default); beyond the queue bound, requests are refused with a retry hint. Size the pool for your load.
By format
| Format | File types | What to expect |
|---|---|---|
| Word | .docx, .docm, .doc, .dotx, .odt, .rtf | Pages and page numbers as in the original. Macros in .docm are never run. |
| Excel | .xlsx, .xlsm, .xls, .xltx, .ods, .csv | Every sheet as a read-only preview with its charts and formatting. No grid, filtering or formula bar; macros in .xlsm are never run. |
| PowerPoint | .pptx, .pptm, .ppt, .ppsx, .potx, .odp | Every slide as authored, one per page. Animations and transitions are flattened. |
.pdf | Plain PDFs are served byte for byte, with text search. PDFs with JavaScript, auto-open actions or attachments are rebuilt from their pages, so embedded files (for example ZUGFeRD invoice XML) are not shown. |
Complex workbooks and slides can differ visibly from Office Online Server in fine detail. Missing content or broken pagination is a defect we fix.
Roadmap
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 with no release date yet. Early customers become design partners and help decide what we build next.
FAQ
Can I edit documents?
Not yet. Office Render Engine is view-only today. Editing in the browser is in development, without a release date.
Is Excel interactive?
No. Workbooks are shown as faithful previews, without a scrolling grid, filtering or formula bar. This is the largest functional gap compared with Office Online Server.
Do documents look exactly like in Office Online Server?
They look faithful, not pixel-identical. Line breaks and page counts match; small differences in font rendering and spacing are expected. Missing content or broken pagination is treated as a defect.