Definition. A preview in OfficeAPI is a rendered view of an office document produced for display inside your product, so a user can see the file without downloading it or opening another application. The list of supported extensions comes from the product documentation and is shown on the preview page.
How many formats can OfficeAPI preview?
32 extensions across 3 families: 13 Word, 11 Excel, and 8 PowerPoint. All of them render fully offline on the 6 supported operating systems.
Word (13)
.docx, .dotx, .docm, .dotm, .doc, .dot, .wps, .wpt, .odt, .ofd, .rtf, .epub, .txt
Excel (11)
.xlsx, .xlsm, .xltx, .xltm, .xlsb, .xls, .xlt, .et, .ett, .csv, .ods
PowerPoint (8)
.pptx, .pptm, .potx, .potm, .ppt, .dps, .dpt, .odp
How does preview differ from conversion?
| Preview | Conversion | |
|---|---|---|
| Result | A rendered view shown in your UI | A new file in another documented format |
| Documented coverage | 32 extensions | 42 input/output pairs |
| Extra formats | .epub, .txt, .ofd, .xlsb can be previewed |
Not conversion inputs |
| Engine | Same Rust core | Same Rust core |
Preview and conversion share the engine but have separate lists. Always check the list that matches the surface you are building.
How do you add a preview to your product?
- Confirm the file's extension is in the three lists above.
- Pass the file to OfficeAPI through the dynamic library or process invocation, on the device or server where the file already lives.
- Display the rendered result in your own interface. No hosted viewer is involved.
Frequently asked questions
Can OfficeAPI preview a PDF?
PDF is not in the documented preview list; it is a conversion input and output. Convert the PDF to a supported format or show it with your own PDF viewer.
Can OfficeAPI preview .xlsb or .epub?
Yes. Both are documented preview extensions even though they are not conversion inputs.
Where is the preview rendered?
Wherever OfficeAPI runs: on the user's device or on servers you manage. Nothing is sent to a hosted viewer.