Configure markup

Default handler

Hugo uses Goldmark to render Markdown to HTML.

hugo.

markup:
  defaultMarkdownHandler: goldmark

[markup]
  defaultMarkdownHandler = 'goldmark'

{
   "markup": {
      "defaultMarkdownHandler": "goldmark"
   }
}

Files with the .md or .markdown extension are processed as Markdown, provided that you have not specified a different content format using the markup field in front matter.

To use a different renderer for Markdown files, specify one of asciidocext, org, pandoc, or rst in your site configuration.

defaultMarkdownHandler	Description
`asciidocext`	AsciiDoc
`goldmark`	Goldmark
`org`	Emacs Org Mode
`pandoc`	Pandoc
`rst`	reStructuredText

To use AsciiDoc, Pandoc, or reStructuredText you must install the relevant renderer and update your security policy.

Goldmark

This is the default configuration for the Goldmark Markdown renderer:

hugo.

markup:
  goldmark:
    duplicateResourceFiles: false
    extensions:
      cjk:
        eastAsianLineBreaks: false
        eastAsianLineBreaksStyle: simple
        enable: false
        escapedSpace: false
      definitionList: true
      extras:
        insert:
          enable: false
        mark:
          enable: false
        subscript:
          enable: false
        superscript:
          enable: false
      footnote: true
      linkify: true
      linkifyProtocol: https
      passthrough:
        delimiters:
          block: []
          inline: []
        enable: false
      strikethrough: true
      table: true
      taskList: true
      typographer:
        apostrophe: '&rsquo;'
        disable: false
        ellipsis: '&hellip;'
        emDash: '&mdash;'
        enDash: '&ndash;'
        leftAngleQuote: '&laquo;'
        leftDoubleQuote: '&ldquo;'
        leftSingleQuote: '&lsquo;'
        rightAngleQuote: '&raquo;'
        rightDoubleQuote: '&rdquo;'
        rightSingleQuote: '&rsquo;'
    parser:
      attribute:
        block: false
        title: true
      autoHeadingID: true
      autoHeadingIDType: github
      wrapStandAloneImageWithinParagraph: true
    renderHooks:
      image:
        enableDefault: false
      link:
        enableDefault: false
    renderer:
      hardWraps: false
      unsafe: false
      xhtml: false

[markup]
  [markup.goldmark]
    duplicateResourceFiles = false
    [markup.goldmark.extensions]
      definitionList = true
      footnote = true
      linkify = true
      linkifyProtocol = 'https'
      strikethrough = true
      table = true
      taskList = true
      [markup.goldmark.extensions.cjk]
        eastAsianLineBreaks = false
        eastAsianLineBreaksStyle = 'simple'
        enable = false
        escapedSpace = false
      [markup.goldmark.extensions.extras]
        [markup.goldmark.extensions.extras.insert]
          enable = false
        [markup.goldmark.extensions.extras.mark]
          enable = false
        [markup.goldmark.extensions.extras.subscript]
          enable = false
        [markup.goldmark.extensions.extras.superscript]
          enable = false
      [markup.goldmark.extensions.passthrough]
        enable = false
        [markup.goldmark.extensions.passthrough.delimiters]
          block = []
          inline = []
      [markup.goldmark.extensions.typographer]
        apostrophe = '&rsquo;'
        disable = false
        ellipsis = '&hellip;'
        emDash = '&mdash;'
        enDash = '&ndash;'
        leftAngleQuote = '&laquo;'
        leftDoubleQuote = '&ldquo;'
        leftSingleQuote = '&lsquo;'
        rightAngleQuote = '&raquo;'
        rightDoubleQuote = '&rdquo;'
        rightSingleQuote = '&rsquo;'
    [markup.goldmark.parser]
      autoHeadingID = true
      autoHeadingIDType = 'github'
      wrapStandAloneImageWithinParagraph = true
      [markup.goldmark.parser.attribute]
        block = false
        title = true
    [markup.goldmark.renderHooks]
      [markup.goldmark.renderHooks.image]
        enableDefault = false
      [markup.goldmark.renderHooks.link]
        enableDefault = false
    [markup.goldmark.renderer]
      hardWraps = false
      unsafe = false
      xhtml = false

{
   "markup": {
      "goldmark": {
         "duplicateResourceFiles": false,
         "extensions": {
            "cjk": {
               "eastAsianLineBreaks": false,
               "eastAsianLineBreaksStyle": "simple",
               "enable": false,
               "escapedSpace": false
            },
            "definitionList": true,
            "extras": {
               "insert": {
                  "enable": false
               },
               "mark": {
                  "enable": false
               },
               "subscript": {
                  "enable": false
               },
               "superscript": {
                  "enable": false
               }
            },
            "footnote": true,
            "linkify": true,
            "linkifyProtocol": "https",
            "passthrough": {
               "delimiters": {
                  "block": [],
                  "inline": []
               },
               "enable": false
            },
            "strikethrough": true,
            "table": true,
            "taskList": true,
            "typographer": {
               "apostrophe": "\u0026rsquo;",
               "disable": false,
               "ellipsis": "\u0026hellip;",
               "emDash": "\u0026mdash;",
               "enDash": "\u0026ndash;",
               "leftAngleQuote": "\u0026laquo;",
               "leftDoubleQuote": "\u0026ldquo;",
               "leftSingleQuote": "\u0026lsquo;",
               "rightAngleQuote": "\u0026raquo;",
               "rightDoubleQuote": "\u0026rdquo;",
               "rightSingleQuote": "\u0026rsquo;"
            }
         },
         "parser": {
            "attribute": {
               "block": false,
               "title": true
            },
            "autoHeadingID": true,
            "autoHeadingIDType": "github",
            "wrapStandAloneImageWithinParagraph": true
         },
         "renderHooks": {
            "image": {
               "enableDefault": false
            },
            "link": {
               "enableDefault": false
            }
         },
         "renderer": {
            "hardWraps": false,
            "unsafe": false,
            "xhtml": false
         }
      }
   }
}

Goldmark extensions

The extensions below, excluding Extras and Passthrough, are enabled by default.

Extension	Documentation	Enabled
cjk	Goldmark Extensions: CJK	✔️
definitionList	PHP Markdown Extra: Definition lists	✔️
extras	Hugo Goldmark Extensions: Extras
footnote	PHP Markdown Extra: Footnotes	✔️
linkify	GitHub Flavored Markdown: Autolinks	✔️
passthrough	Hugo Goldmark Extensions: Passthrough
strikethrough	GitHub Flavored Markdown: Strikethrough	✔️
table	GitHub Flavored Markdown: Tables	✔️
taskList	GitHub Flavored Markdown: Task list items	✔️
typographer	Goldmark Extensions: Typographer	✔️

Extras extension

New in v0.126.0

Configure the extras extension to enable inserted text, mark text, subscript, and superscript elements in Markdown.

Element	Markdown	Rendered
Inserted text	`++foo++`	`<ins>foo</ins>`
Mark text	`==bar==`	`<mark>bar</mark>`
Subscript	`H~2~O`	`H<sub>2</sub>O`
Superscript	`1^st^`	`1<sup>st</sup>`

Passthrough extension

New in v0.122.0

Enable the passthrough extension to include mathematical equations and expressions in Markdown using LaTeX or TeX typesetting syntax. See mathematics in Markdown for details.

Typographer extension

The Typographer extension replaces certain character combinations with HTML entities as specified below:

Markdown	Replaced by	Description
`...`	`…`	horizontal ellipsis
`'`	`’`	apostrophe
`--`	`–`	en dash
`---`	`—`	em dash
`«`	`«`	left angle quote
`“`	`“`	left double quote
`‘`	`‘`	left single quote
`»`	`»`	right angle quote
`”`	`”`	right double quote
`’`	`’`	right single quote

Goldmark settings explained

Most of the Goldmark settings above are self-explanatory, but some require explanation.

duplicateResourceFiles

New in v0.123.0

(bool) If true, shared page resources on multilingual single-host sites will be duplicated for each language. See multilingual page resources for details. Default is false.

parser.wrapStandAloneImageWithinParagraph

(bool) If true, image elements without adjacent content will be wrapped within a p element when rendered. This is the default Markdown behavior. Set to false when using an image render hook to render standalone images as figure elements. Default is true.

parser.autoHeadingIDType

(string) The strategy used to automatically generate heading id attributes, one of github, github-ascii or blackfriday.

github produces GitHub-compatible id attributes
github-ascii drops any non-ASCII characters after accent normalization
blackfriday produces id attributes compatible with the Blackfriday Markdown renderer

This is also the strategy used by the anchorize template function. Default is github.

parser.attribute.block

(bool) If true, enables Markdown attributes for block elements. Default is false.

parser.attribute.title

(bool) If true, enables Markdown attributes for headings. Default is true.

renderHooks.image.enableDefault

New in v0.123.0

(bool) If true, enables Hugo’s embedded image render hook. Default is false.

renderHooks.link.enableDefault

New in v0.123.0

(bool) If true, enables Hugo’s embedded link render hook. Default is false.

renderer.hardWraps

(bool) If true, Goldmark replaces newline characters within a paragraph with br elements. Default is false.

renderer.unsafe

(bool) If true, Goldmark renders raw HTML mixed within the Markdown. This is unsafe unless the content is under your control. Default is false.

AsciiDoc

This is the default configuration for the AsciiDoc renderer:

hugo.

markup:
  asciidocExt:
    attributes: {}
    backend: html5
    extensions: []
    failureLevel: fatal
    noHeaderOrFooter: true
    preserveTOC: false
    safeMode: unsafe
    sectionNumbers: false
    trace: false
    verbose: false
    workingFolderCurrent: false

[markup]
  [markup.asciidocExt]
    backend = 'html5'
    extensions = []
    failureLevel = 'fatal'
    noHeaderOrFooter = true
    preserveTOC = false
    safeMode = 'unsafe'
    sectionNumbers = false
    trace = false
    verbose = false
    workingFolderCurrent = false
    [markup.asciidocExt.attributes]

{
   "markup": {
      "asciidocExt": {
         "attributes": {},
         "backend": "html5",
         "extensions": [],
         "failureLevel": "fatal",
         "noHeaderOrFooter": true,
         "preserveTOC": false,
         "safeMode": "unsafe",
         "sectionNumbers": false,
         "trace": false,
         "verbose": false,
         "workingFolderCurrent": false
      }
   }
}

AsciiDoc settings explained

attributes

(map) A map of key-value pairs, each a document attributes,See Asciidoctor’s attributes.

backend

(string) The backend output file format. Default is html5.

extensions

(string array) An array of enabled extensions, one or more of asciidoctor-html5s, asciidoctor-bibtex, asciidoctor-diagram, asciidoctor-interdoc-reftext, asciidoctor-katex, asciidoctor-latex, asciidoctor-mathematical, or asciidoctor-question.

failureLevel

(string) The minimum logging level that triggers a non-zero exit code (failure). Default is fatal.

noHeaderOrFooter

(bool) If true, outputs an embeddable document, which excludes the header, the footer, and everything outside the body of the document. Default is true.

preserveTOC

(bool) If true, preserves the table of contents (TOC) rendered by Asciidoctor. By default, to make the TOC compatible with existing themes, Hugo removes the TOC rendered by Asciidoctor. To render the TOC, use the TableOfContents method on a Page object in your templates. Default is false.

safeMode

(string) The safe mode level, one of unsafe, safe, server, or secure. Default is unsafe.

sectionNumbers

(bool) If true, numbers each section title. Default is false.

trace

(bool) If true, include backtrace information on errors. Default is false.

verbose

(bool)If true, verbosely prints processing information and configuration file checks to stderr. Default is false.

workingFolderCurrent

(bool) If true, sets the working directory to be the same as that of the AsciiDoc file being processed, allowing includes to work with relative paths. Set to true to render diagrams with the asciidoctor-diagram extension. Default is false.

AsciiDoc configuration example

hugo.

markup:
  asciidocExt:
    attributes:
      my-attribute-name: my value
      my-base-url: https://example.com/
    extensions:
    - asciidoctor-html5s
    - asciidoctor-diagram
    workingFolderCurrent: true

[markup]
  [markup.asciidocExt]
    extensions = ['asciidoctor-html5s', 'asciidoctor-diagram']
    workingFolderCurrent = true
    [markup.asciidocExt.attributes]
      my-attribute-name = 'my value'
      my-base-url = 'https://example.com/'

{
   "markup": {
      "asciidocExt": {
         "attributes": {
            "my-attribute-name": "my value",
            "my-base-url": "https://example.com/"
         },
         "extensions": [
            "asciidoctor-html5s",
            "asciidoctor-diagram"
         ],
         "workingFolderCurrent": true
      }
   }
}

AsciiDoc troubleshooting

Run hugo --logLevel debug to examine Hugo’s call to the Asciidoctor executable:

INFO 2019/12/22 09:08:48 Rendering book-as-pdf.adoc with C:\Ruby26-x64\bin\asciidoctor.bat using asciidoc args [--no-header-footer -r asciidoctor-html5s -b html5s -r asciidoctor-diagram --base-dir D:\prototypes\hugo_asciidoc_ddd\docs -a outdir=D:\prototypes\hugo_asciidoc_ddd\build -] ...

Highlight

This is the default highlight configuration. Note that some of these settings can be set per code block, see Syntax Highlighting.

hugo.

markup:
  highlight:
    anchorLineNos: false
    codeFences: true
    guessSyntax: false
    hl_Lines: ""
    hl_inline: false
    lineAnchors: ""
    lineNoStart: 1
    lineNos: false
    lineNumbersInTable: true
    noClasses: true
    noHl: false
    style: monokai
    tabWidth: 4

[markup]
  [markup.highlight]
    anchorLineNos = false
    codeFences = true
    guessSyntax = false
    hl_Lines = ''
    hl_inline = false
    lineAnchors = ''
    lineNoStart = 1
    lineNos = false
    lineNumbersInTable = true
    noClasses = true
    noHl = false
    style = 'monokai'
    tabWidth = 4

{
   "markup": {
      "highlight": {
         "anchorLineNos": false,
         "codeFences": true,
         "guessSyntax": false,
         "hl_Lines": "",
         "hl_inline": false,
         "lineAnchors": "",
         "lineNoStart": 1,
         "lineNos": false,
         "lineNumbersInTable": true,
         "noClasses": true,
         "noHl": false,
         "style": "monokai",
         "tabWidth": 4
      }
   }
}

For style, see these galleries:

For CSS, see Generate Syntax Highlighter CSS.

This is the default configuration for the table of contents, applicable to Goldmark and Asciidoctor:

hugo.

markup:
  tableOfContents:
    endLevel: 3
    ordered: false
    startLevel: 2

[markup]
  [markup.tableOfContents]
    endLevel = 3
    ordered = false
    startLevel = 2

{
   "markup": {
      "tableOfContents": {
         "endLevel": 3,
         "ordered": false,
         "startLevel": 2
      }
   }
}

startLevel

(int) Heading levels less than this value will be excluded from the table of contents. For example, to exclude h1 elements from the table of contents, set this value to 2. Default is 2.

endLevel

(int) Heading levels greater than this value will be excluded from the table of contents. For example, to exclude h4, h5, and h6 elements from the table of contents, set this value to 3. Default is 3.

ordered

(bool) If true, generates an ordered list instead of an unordered list. Default is false.

Configure markup

Default handler

Goldmark

Goldmark extensions

Extras extension

Passthrough extension

Typographer extension

Goldmark settings explained

duplicateResourceFiles

parser.wrapStandAloneImageWithinParagraph

parser.autoHeadingIDType

parser.attribute.block

parser.attribute.title

renderHooks.image.enableDefault

renderHooks.link.enableDefault

renderer.hardWraps

renderer.unsafe

AsciiDoc

AsciiDoc settings explained

attributes

backend

extensions

failureLevel

noHeaderOrFooter

preserveTOC

safeMode

sectionNumbers

trace

verbose

workingFolderCurrent

AsciiDoc configuration example

AsciiDoc troubleshooting

Highlight

Table of contents

startLevel

endLevel

ordered

See also

Last updated: May 14, 2024: Document the Goldmark extras extension (653069a0d)