Supported file types

Sinch Fax API supports the following file types:

• Microsoft Word documents (.docx)
• HTML documents (.html)
• Images(.jpg, .png, .tif)
• PDFs (.pdf)
• Plain text files (.txt)

We recommend that you send either an image like a .png or a PDF to keep any formatting on the document.

PDF considerations

Some PDFs are editable or form-fillable. To preserve the information entered in these form fields, you should "flatten" the PDF. You can flatten a PDF using the following methods:

• Using software like Adobe Acrobat
• Print to PDF using your browser ( Chrome , Edge , Safari , Firefox )