What you can upload — and why some files are refused
PDF, Word and plain text become documents. Everything else is turned away with a reason.
SignSpry accepts three kinds of document:
| Format | What happens |
|---|---|
PDF (.pdf) | Used as-is. Nothing is re-encoded. |
Word (.docx) | Converted to a PDF when you upload it. |
Plain text (.txt) | Laid out as an A4 PDF, keeping your line breaks and indentation. |
Word and text are converted because everything downstream — page geometry, field placement, flattening, sealing — is built on a document with fixed pages. A file that reflows would move your signature box.
The same rules apply everywhere: the browser upload, Add document on the prepare screen, template upload, the cloud-link importer and the REST API.
Limits
- 50 MB per file, and up to 10 files per envelope.
- Plain text is capped at 2 MB — that's already around 600 pages.
Why a file gets refused
Every upload is checked twice: the extension has to be one we accept, and the actual bytes have to match. That catches two different mistakes.
An executable renamed to .pdf is refused because the content isn't a PDF. And script.js is refused even though it is technically text, because the extension says it isn't a document. Both checks have to agree.
When a file is turned away you get a message that says what to do next, not just "invalid file":
| You uploaded | What you'll see |
|---|---|
| A JPEG or PNG | Images can't be signed directly — put it in a Word file or export a PDF |
A legacy .doc | Open it in Word or Google Docs and save as .docx or PDF |
| An Excel or PowerPoint file | Export it as a PDF and upload that |
A .zip | Upload the document inside it, not the archive |
.pages, .odt, .rtf | Export as PDF or Word .docx |
Documents your signers upload
A File upload field lets a signer attach something — an ID proof, a photograph, a purchase order. Those follow their own rules and can be images as well as PDFs, because they're appended to the finished envelope rather than signed. See Field types.