Folio Writer
Compiling on iPhone and iPad
An iPhone can't run pandoc or LaTeX, so Folio Writer for iOS typesets on the Folio Cloud server — briefly, transparently, and only when you ask. Here is what happens, what you can choose, and when to use the Mac instead.
Two ways to get a PDF
Preview Manuscript (free) assembles the whole draft and renders it on the device, with math set by KaTeX; its share menu makes a PDF or prints, and nothing leaves the phone. It is the quick, private route for a reading copy.
Compile (Pro) is the real typeset — the same pandoc pipeline the Mac uses — producing a PDF via Typst or LaTeX, a Word document, or Typst source, with citations resolved against your .bib files and figures, tables and equations numbered. It runs on the server.
What is sent, and for how long
A project that already lives on Folio Cloud is compiled from the server's copy: nothing extra is uploaded. A local or iCloud project is packaged and sent for the compile — it needs your Folio Cloud account signed in — and is deleted when the compile finishes; the server sweeps anything left after a few minutes regardless. An end-to-end encrypted project asks before sending one readable copy, since its cloud copy is sealed. The first time you compile, a notice explains all of this once.
Server compilation is only for iPhone and iPad. On a Mac, Folio Writer compiles locally with its own tools, and the file never leaves your computer.
The options
Format: PDF, Word, or Typst source. Typesetter (PDF only): Typst, the default — fast, with CJK fonts and SVG figures handled natively — or LaTeX, run through Tectonic, for the look of a LaTeX document and the packages that come with it; the line under the finished file says which one actually set it. Insert binder titles as headings prints folder and document titles at their depth in the binder, as the Mac does; Skip a document's first heading if it repeats its title avoids printing a title twice. Number sections and Table of contents do what they say, and a manuscript with suggested edits can be compiled with every suggestion accepted or every one rejected.
Export Markdown (source) writes the assembled manuscript as one .md on the device — the same text the compile would send — for a collaborator, a repository, or another tool.
Cross-references and the reference list
The server runs pandoc-crossref, so @fig:key, @tbl:key and @eq:key become “Fig. 1”, “Table 1” and “eq. 1”, numbered in order, and a capitalised @Fig:key starts a sentence. When the text cites anything from the bibliography, a References section is appended under its own unnumbered heading; put a ::: {#refs} block in the manuscript yourself to place it elsewhere. See Figures, equations and cross-references for the syntax.
Long projects
A compile runs as a job: the phone submits the manuscript, polls for progress (“converting”, “typesetting with LaTeX…”), then fetches the file, so a long book is never cut short by a request timeout. Cancel stops the typesetter on the server. If a compile fails, the first lines of the Problem box are the actual error — a LaTeX error with its line number, or pandoc's message — followed by any warnings.
Your own server. The official Folio Cloud already offers end-to-end encryption and password-protected sharing, but advanced users — and companies, universities, institutions and research groups that must keep everything on their own infrastructure — can run the Folio Cloud server themselves. See Self-hosting, or get in touch for more information and technical support.