The short version: DocuBuild decides what it can accept from the file's extension — the bit after the last dot. If the extension is on the list below, the file uploads. If it isn't, you're told before any data leaves your computer.
The full list
| Category | Extensions |
|---|---|
| Documents | .pdf .doc .docx .xls .xlsx .ppt .pptx .txt |
| Drawings & models | .dwg .dwf .ifc .rvt .rfa .stp .step .stp and .step are the same format under two spellings — both work. |
| Images | .png .jpg .jpeg .gif .svg |
| Video | .mp4 .mov .avi .wmv .flv .webm .mkv .mpeg .mpg .m4v |
| Archives | .zip |
BIM and CAD formats were added in August 2026 — .ifc, .rvt, .rfa, .stp and .step. If you tried one of these before and were turned away, try again.
What the rejection message means
There are two, and they say different things.
| 1 | “.xyz files are not supported.” The extension isn't on the list above. See the options below. |
| 2 | “…has no file extension, so DocuBuild cannot tell what type it is.” The file name has no dot-suffix at all — common with files pulled off a scanner, out of an email attachment, or renamed on a Mac with extensions hidden. Rename it with the correct extension and upload again. |
Nothing is transferred before the check runs. This wasn't always true. Until August 2026 the browser sent the entire file first and only failed at the last step — one customer transferred the same 2.65 GB model twice before being told the format wasn't supported. The check now happens the moment you pick the file.
If your file isn't on the list
For anything that will be read rather than opened in software — certificates, test results, sign-offs, warranties — PDF is the right format anyway. It previews in the browser, it can be reviewed and commented on in place, and it is what a certifier expects to receive.
A ZIP archive is accepted whatever it contains, so it covers native files with no supported extension of their own — a Navisworks file, a point cloud, a folder of survey data, a software project export. The trade-off is that DocuBuild treats it as one opaque document: no preview, and no search inside it.
The list grows in response to what customers actually send — the BIM and CAD formats were added because production data showed those were the ones being turned away. If a format matters on your projects, email support@docubuild.io and tell us which one and how often.
Related limits worth knowing
- 30 files per batch. Select more and DocuBuild takes the first 30 and tells you how many were left out — upload the rest in a second batch.
- Extension, not content. A ZIP renamed to
.pdfwill be accepted at upload and will simply fail to preview afterwards. Send files with their real extensions. - File names. If names arrive shortened, with a tilde like
REPORT~1.PDF, that's a separate Windows issue — see why file names look shortened after uploading from Windows.