How to convert TXT to RTF on iPhone

Rich Text Format is a document format Microsoft published in the 1980s that essentially every word processor still reads: Word, Pages, TextEdit, WordPad, LibreOffice, Google Docs. It stores text along with formatting — fonts, sizes, bold, italic, colours, alignment — as a stream of text-based control words rather than a binary blob.

It became the universal interchange format precisely because it is boring, documented, and owned by nobody in practice. If you need to hand a formatted document to a person whose software you cannot predict, RTF still beats every alternative except PDF.

It writes your text into a valid RTF document with a plain 12-point default font, keeping your line and paragraph breaks. That is the whole operation.

It is worth saying what it does not do, because "rich text" invites the wrong expectation: it does not add formatting. Your text file contains no headings, no bold, no italics — that information was never in it — so none appears in the RTF. What you get is a document that a word processor will open, place a cursor in, and let you format yourself. The conversion moves the text into a container where formatting becomes possible; it does not guess at what you wanted.

If you want structure to survive automatically, the source has to carry it. Write in Markdown instead, and headings, bold, lists and links convert through to a formatted RTF — Markdown to RTF is supported directly.

People try this, and it is worth explaining why it fails. An RTF file is not plain text with a different extension — it is a specific syntax. A real RTF begins with a control word like {\rtf1\ansi...}, and braces and backslashes inside it are structure, not characters.

Rename a .txt to .rtf and you hand a word processor a file whose extension promises RTF and whose contents are not RTF. Depending on the app you get an error, a fallback to plain text, or a wall of literal control words.

The other half of the problem is your own content. If your text file contains a backslash or a curly brace — a Windows file path, a snippet of code, a JSON fragment — those characters mean something in RTF's syntax. A converter that writes RTF naively produces a document that is subtly corrupt: a stray brace silently swallows the rest of your text. Convexy writes RTF through the system's own RTF writer, which escapes those characters properly and encodes non-ASCII text — accents, curly quotes, other alphabets — the way the format requires. That is the actual value of this conversion over a rename.

Choose RTF when the recipient will edit the document, or when a system specifically asks for .rtf — some submission portals, legal templates, and older corporate workflows still do. It is also the sensible way to get plain text into Word or Pages as a document rather than as a pasted blob.

Choose PDF instead when nobody should edit it and the layout must be identical everywhere. That is the more common need, and it is what most people actually mean when they say they want to "convert a text file to a document".

Choose HTML or Markdown instead when the destination is the web or a notes app. A text file converts to all four.

Convexy does not read or write DOC or DOCX. If your goal is a Word file, converting to RTF and opening it in Word is the closest this app gets — Word will open the RTF happily, and you can save it as a .docx from there if you need that specific extension. There is no path in Convexy that produces a .docx directly, and there will not be one hidden behind a purchase.