content/line-length

Reports lines in headings, code blocks, and tables that are longer than a limit, 80 columns by default. It never edits, because splitting these lines can change their meaning; paragraphs are left to style/wrap, which reflows them.

Problem rule, reported only. Presets: none. Dialects: all. Options: lineLength, headingLineLength, codeBlockLineLength, headings, codeBlocks, tables, strict, stern, measure.

With { "lineLength": 40 }, reported:

## Configuring the formatter and the linter for a large workspace

Not reported, because it is a paragraph:

Configuring the formatter and the linter for a large workspace takes one file.

Option	Values	Default
lineLength	Nonnegative integer; zero disables the limit	80
headingLineLength	Nonnegative integer	lineLength
codeBlockLineLength	Nonnegative integer	lineLength
headings	Boolean	true
codeBlocks	Boolean	true
tables	Boolean	true
strict	Boolean	false
stern	Boolean	false
measure	"columns" or "codepoints"	"columns"

• lineLength: the limit for every checked line, and for tables the only one. Zero turns the limit off.
• headingLineLength, codeBlockLineLength: separate limits for headings and for code blocks; zero turns that limit off.
• headings, codeBlocks, tables: with false, lines of that kind are not checked.
• strict, stern: by default a line is not reported when only its last word, which holds no blank space, crosses the limit. stern reports such a line when it has more than one word; strict reports every long line and takes precedence.
• measure: as in style/wrap, columns counts display columns, so CJK characters and combining marks are measured as they show, and codepoints counts Unicode code points, for policies about the source. Tabs count up to the next multiple of four columns.

{
  "rules": {
    "content/line-length": ["warn", { "lineLength": 100, "codeBlocks": false }],
  },
}

Edge cases and advanced usage

Details: each physical line of # and underlined headings, fenced and indented code blocks, fence lines included, and parsed tables is measured whole, so list and block quote markers count toward the width.

Not checked: paragraphs, front matter, HTML, math, reference definitions, thematic breaks, and every other block. A table in a dialect without table syntax is a paragraph, so it is not checked either. Markdownlint's MD013 checks HTML and math lines too, but skips front matter and definitions, and, outside strict checking, lines that hold only a link.

Related rules

style/wrap keeps its own paragraph findings. strict and stern here apply only to headings, code, and tables, and do not imply its reportUnreflowed or reportUnbreakable, which judge where prose can safely break and which pieces cannot be split, not raw blank space.