MDViewer

Quick start

2026-07-27 477 words 3 min read

Three ways to open local Markdown, a tour of the layout, and the file types supported.

Getting started

MDViewer renders Markdown in two places: the in-browser reader, which opens files straight from your own computer, and these documentation pages. Both use the same rendering engine and theme, so what you see here is exactly how your own files will look.

Opening local files

Go back to the reader home page and use any of these:

Method How Best for
Open a folder Click “Open folder”, or press O Reading a whole library, with search and links across files
Open a single file Click “Open single file”, or press Shift+O Reading just one document
Drag and drop Drop a folder or .md file anywhere on the page The fastest route

Note

Your files are never uploaded to any server. Reading and rendering happen entirely inside the browser, and everything is released when you close the tab.

Browser support

Opening a folder relies on the File System Access API :

  • Chrome / Edge / Opera 86+: full support, including remembering the last folder you opened
  • Safari / Firefox: falls back to <input webkitdirectory> and drag-and-drop. Reading works fine, but the browser cannot remember the folder — you have to pick it again each time.

Session restore

When you open a folder in a supported browser, the directory handle is stored in IndexedDB. Next time you visit:

  • If the permission is still valid, you return automatically to the file and scroll position you left
  • If it has expired, a “continue reading” prompt appears in the corner; one click re-grants access

The “Recently opened” list on the home page keeps your last 8 workspaces.

The layout

  • File tree on the left: expands by directory level; the box at the top filters by file name; B collapses it
  • Content in the middle: width, type size, line height and typeface are all adjustable in the settings; , opens them
  • Outline on the right: generated from level 2 to level 4 headings, highlighting the current section as you scroll; T collapses it

Supported file types

When scanning a directory the reader picks up:

  • Documents: .md .markdown .mdown .mkd .mdx .txt
  • Images: .png .jpg .gif .svg .webp .avif .bmp .ico (so relative paths in Markdown resolve)

It skips .git, node_modules, dist, build, .obsidian and similar directories, along with every hidden file starting with .. A single scan covers at most 6000 files and 12 levels of depth.

Relative paths

Images and links written like this all work:

1
2
3
4
5

![Architecture](./images/arch.png)
![Image one level up](../assets/logo.svg)

[Jump to another page](./advanced/config.md)
[Section index](../guide/)

Images are located within the workspace and turned into local blob URLs; .md links navigate inside the reader without reloading the page. Targets that cannot be found are marked in red with an explanation.

Next steps