TL;DR: Markdown cuts token costs and stays readable as plain text, but raw syntax isn’t everyone’s idea of a good time. My two favorites cover both sides of the problem, VS Code and its built-in Markdown preview for writing and MDHero for reading, Pandoc keeps Word documents in the mix, and several other free options fill in the gaps.
Why Markdown
Markdown carries structure (headings, lists, links, emphasis) with a handful of punctuation marks instead of the packaging that comes with HTML or a DOCX file. The gap is big enough to show up on the bill: Markdown runs roughly 65 to 90 percent fewer tokens than DOCX for the same content, and that compounds with every round of edits (see Efficient Claude Usage with Microsoft Word Documents for the full rant).
HTML has its own fan club, and the claim that it is the new Markdown holds up in one narrow case: an LLM producing a deliverable a human has to read and navigate. For model input, internal agent loops, and repository documentation, Markdown still wins, at around 80 percent fewer tokens than HTML for equivalent content (see Markup is the New Markdown for the scenario breakdown). That leaves the practical question of which app to use with it.
Developers Already Have an Editor and Everyone Else Needs a Viewer
For developers, and for anyone braving VS Code to get a better look at what their AI is doing, the editor is already installed. VS Code has a built-in Markdown preview that runs side by side with the raw file or as a full-page view (Ctrl+Shift+V for the full page, Ctrl+K then V for side by side, Cmd on a Mac). The file on disk is still plain Markdown, and it sits in the same folder as the code, prompts, and docs it belongs with.
Asking a colleague to install a developer environment just to read a README is a good way to ensure it goes unread. The new Windows Notepad has picked up Markdown “support,” which does some heavy lifting next to a purpose-built reader. MDHero is a free, open source viewer at under 8MB that renders the file cleanly and otherwise gets out of the way (no vault, no sync, no plugin marketplace, no account). When the goal is to read a document, less app is the feature, and it is small enough to hand to a non-technical teammate without a lecture attached.
Documents Bound for Word Can Still Be Worked in Markdown
Plenty of documents start in Word and end in Word, and nobody is about to change that. It doesn’t mean Word has to be the place where the AI-assisted work happens. Pandoc is a free, open source converter that turns a DOCX into Markdown and back again, so the drafting and revising can happen in the cheap format and only the finish happens in the expensive one. Word plugins for Claude improve the ergonomics but leave the same DOCX overhead underneath, so the token bill stays put (see Efficient Claude Usage with Microsoft Word Documents for the full workflow and the numbers behind it).
The short version, in two commands:
pandoc input.docx -o draft.md
pandoc draft.md -o final.docxConvert the existing document to Markdown, do the thinking and editing there with AI, convert back, and apply styling and branding in Word last. Pointing Pandoc at a styled template with --reference-doc=template.docx on the way back carries fonts and headings into the result. Complex tables, tracked changes, and heavily designed layouts may not survive the round trip cleanly, so keep the original DOCX around for anything exotic.
The Rest of the Free Field
These are the other popular free options, roughly sorted by what they are best at:
- Obsidian: A local-first notes app built on a folder of Markdown files, with backlinks, a graph view, and a large plugin ecosystem. Free for personal use. It is a knowledge base first and an editor second, so expect a learning curve.
- MarkText: A free, open source editor that renders as you type, with a clean interface and no account. Check the project’s recent activity before standardizing on it, since update cadence has been uneven.
- Zettlr: Free, open source, and aimed at academic and long-form writing, with citation support and Pandoc export.
- Joplin: Free, open source note-taking in Markdown with sync across desktop and mobile through the storage service of your choice. It also has a good WYSIWYG mode, which makes it the easiest pick here for anyone who would rather never see the syntax.
- Notepad++: Markdown is text, so any text editor opens it (syntax highlighting is the only upgrade needed).
Typora, one of the best-known Markdown editors, is left off this list because it is paid, and this list is free only (psst…Claude made me say that…I never heard of it before it edited this post).
I spent years mastering HTML, and found the shift to markdown a bit annoying at first. I’m embracing not as something I personally find better, but as something that people (and now machines) that I would to communicate with have adopted as their preference. The ability to change is not only the sign of a good architecture, it is a requirement for good architects and other creatures.