Does my Word document file need to be in single space or double space, and what margins and font should I use etc?

We recommend that authors use our standard Word template of an article compatible with all journals from JMIR Publications. This can be downloaded from here: https://asset.jmir.pub/assets/public/InstructionsForAuthorsOfJMIR.docx.

There are no explicit formatting requirements, especially for the initial review round. On acceptance, your manuscript will be stripped of all formatting (except italics for highlighting).

We do know that many reviewers prefer to see line numbers, so if possible, please enable this feature for easier review. We also prefer that you use the Heading style to indicate the hierarchy of headings (H1, H2, etc), as shown in the template above, but we are not stringent on other formatting requirements like font type, line spacing, etc.

Feel free to submit your manuscript "as is" without worrying about formatting too much, at least for the initial review round. After acceptance, a professional copyeditor will help you to clean up your manuscript for publication.