Source editor

The source editor on a Markdown file, with its toolbar
  1. Source. Switch to the source editor.
  2. Toolbar. Bold, italic, strikethrough, headings, lists, math, task lists, links, tables and images.

Keyboard shortcuts

On macOS, use Cmd for Ctrl. Select text first to wrap it.

CtrlB**bold**
CtrlI*italic*
CtrlShiftX~~strike~~
CtrlAlt1# heading, with 2 to 6 for the levels below
CtrlM$ $
CtrlDSelect the next match
CtrlAltUpAdd a cursor above
CtrlAltDownAdd a cursor below