Where DOTX came from
DOTX is Word template. It belongs to the word-processor document family, which webp.now handles by rendering the document exactly as it would print and encoding each page as an image.
The technical picture
Compression: Zipped XML or binary container. Transparency: Not applicable. Animation: Not applicable. Colour: Document colour. Typical file size relative to WebP: varies with page count and embedded media.
Where it opens
Word template and compatible office suites. This is usually the deciding factor when choosing between DOTX and WebP — WebP renders in every browser but is uneven in desktop software, while DOTX has a very different support profile.
Converting DOTX to WebP
Each page is rendered exactly as it would print and saved as a WebP image — layout, fonts and graphics frozen into a picture that needs no office software to view and drops straight into a web page. The output is a picture of a document, not a document. Text cannot be selected, searched or edited, so keep the source file for editing.
Converting WebP to DOTX
Convert WebP to DOTX when the destination requires it. Expect the DOTX output to be varies with page count and embedded media — that difference is the price of getting a format the destination will actually accept.