How to Bold Text in Markdown

Bold text renders as a <strong> element in HTML, which means it carries semantic emphasis, not just visual weight. Use it sparingly to call out key terms, warnings, or the single most important phrase in a paragraph. A document where everything is bold communicates nothing — readers scan for the bold parts, so they should mark genuinely important content.

The one edge case that trips people up constantly: bolding part of a word. With asterisks, fan**tas**tic renders the middle of the word in bold. With underscores, fan__tas__tic does not work in CommonMark or GitHub Flavored Markdown, because underscores surrounded by letters are treated as literal characters (this rule exists so snake_case_identifiers do not accidentally trigger formatting). If you ever need intra-word emphasis, asterisks are your only portable option.

Spacing also matters. The opening ** must be immediately followed by a non-space character, and the closing ** must be immediately preceded by one. ** bold ** with spaces inside the markers will render literally as asterisks. Similarly, if you need a literal double asterisk in your text, escape it with backslashes: \*\*not bold\*\*.

Bold combines cleanly with other inline syntax. Triple asterisks give you ***bold and italic*** at once, and you can bold a link by putting the asterisks outside the brackets: **[link text](https://example.com)**. The reverse — putting asterisks inside the link text — also works, but wrapping the whole link is easier to read in source form.