Want to instantly preview finicky markdown files, but don't want to leave your favourite editor, or have to do it in some crappy browser text area? vim-instant-markdown is your friend! When you open a markdown file in Vim, a browser window will open which shows the compiled markdown in real-time, and closes once you close the file in Vim.

As a bonus, github-flavored-markdown is supported, and styles used while previewing are the same as those GitHub uses!

Quick start (assuming you have all the necessary dependencies):

• Install Node.js

• Install the mini-server by running either:

  • [sudo] npm -g install instant-markdown-d

  or the following command for the Python mini-server (which also requires pandoc to render markdown):

  • pip install --user smdv

• Add the following to your .vimrc, depending on the plugin manager of your choice:

  • vim-plug

    Plug 'instant-markdown/vim-instant-markdown', {'for': 'markdown', 'do': 'npm install'}

  • Vundle

    Plugin 'instant-markdown/vim-instant-markdown'

  • Vim8 built-in package manager (Execute the following command instead of adding it to .vimrc)

    # NOTE:
    # 1. Please check you have git installed.
    # 2. Please replace * with a package name you want.
    git clone https://github.com/instant-markdown/vim-instant-markdown.git ~/.vim/pack/*/start/

Detailed instructions

• If you're on Linux, ensure the following packages are installed:
  • xdg-utils
  • curl
  • nodejs (Ensure that you are using a recent stable version. Install node using n if needed.)
• If you're on Windows, you will need into install cURL and put it on your %PATH%.
• If you do not use a plugin manager, copy the ftplugin/markdown/instant-markdown.vim file into ~/.vim/ftplugin/markdown/ (creating directories as necessary),
• Open a markdown file in Vim and enjoy!

Arch-based distributions

• There is a package available on the AUR that installs the plugin:
  • vim-instant-markdown

Minimal default configuration:

filetype plugin on
"Uncomment to override defaults:
"let g:instant_markdown_slow = 1
"let g:instant_markdown_autostart = 0
"let g:instant_markdown_open_to_the_world = 1
"let g:instant_markdown_allow_unsafe_content = 1
"let g:instant_markdown_allow_external_content = 0
"let g:instant_markdown_mathjax = 1
"let g:instant_markdown_mermaid = 1
"let g:instant_markdown_logfile = '/tmp/instant_markdown.log'
"let g:instant_markdown_autoscroll = 0
"let g:instant_markdown_port = 8888
"let g:instant_markdown_python = 1
"let g:instant_markdown_theme = 'dark'

After installing the plugin, execute :help vim-instant-markdown to read more about what the different configuration options imply.

OSX, Linux^, and Windows^^.

_{^ One annoyance in Linux is that there's no way to reliably open a browser page in the background, so you'll likely have to manually refocus your Vim session every time you open a Markdown file. If you have ideas on how to address this I'd love to know!}

_{^^ In Windows, there's no easy way to execute commands asynchronously without popping up a cmd.exe window. Thus, if you run this plugin without g:instant_markdown_slow, you might experience performance issues.}

1. It's not working!

   • Make sure instant-markdown-d was installed and verify using InstantMarkdownDPath.
   • Try to launch with Vim and vim-plug as follows:
     • Install vim-plug
     • Download this minimal.vimrc. (Optional: This minimal file, installs under /tmp. Adjust paths from /tmp if needed).
     • Run vim -u minimal.vimrc +PlugInstall +qall
     • Open any markdown file as vim -u vim -u minimal.vimrc my_markdown_file.md and this plugin should activate.
   • If you're on OSX and are using zsh, try to add set shell=bash\ -i in your .vimrc to set interactive bash as the default Vim shell. (See this issue)

2. How to start it when autostart is off?

   You can use the command :InstantMarkdownPreview to manually start the preview.
   BTW, to disable it, use :InstantMarkdownStop.

If you're curious, the code for the mini-server component for this plugin can be found at {"resolvedServerColorMode":"day"}