!!! warning "" Starting from the version `1.6.0` and earlier, all the options are `disabled` by default in the cli tool. ### backslashEscapesHTMLTags Support escaping of HTML tags. * type: `boolean` * default value: `false` * introduced in: `1.7.2` === "input" ```html \
foo\
``` === "output (value is `true`)" ```html

<div>foo</div>

``` ### completeHTMLDocument Output a complete HTML document, including ``, ``, and `` tags instead of an HTML fragment. * type: `boolean` * default value: `false` * introduced in: `1.8.5` ### customizedHeaderId Set custom ID for a heading. !!! warning "" This option can be overridden with the [`noHeaderId`](#noheaderid) option. * type: `boolean` * default value: `false` * introduced in: `1.7.0` === "code" ```html ## Sample heading {mycustomid} ``` === "output" ```html

This is a heading

``` !!! hint "" For better readability and human-friendliness of the heading IDs, it is also recommended to set the [`ghCompatibleHeaderId`](#ghcompatibleheaderid) option to `true`. ### disableForced4SpacesIndentedSublists Disable the rule of 4 spaces to indent sub-lists. If enabled, this option effectively reverts to the old behavior where you can indent sub-lists with 2 or 3 spaces. * type: `boolean` * default value: `false` * introduced in: `1.5.0` === "input" ``` - one - two ... - one - two ``` === "output (value is `false`)" ```html

...

``` === "output (value is `true`)" ```html

...

``` ### emoji Enable emoji support. For more info on available emojis, see https://github.com/showdownjs/showdown/wiki/Emojis (since v.1.8.0) * type: `boolean` * default value: `false` * introduced in: `1.8.0` === "input" ``` this is a :smile: emoji ``` === "output (value is `false`)" ```html

this is a :smile: emoji

``` === "output (value is `true`)" ```html

this is a 😄 emoji

``` !!! hint "Full list of supported emojies" Check the [Showdown Wiki](https://github.com/showdownjs/showdown/wiki/Emojis#emoji-list) for a full list of supported emojies. ### encodeEmails Enable automatic obfuscation of email addresses. During this process, email addresses are encoded via Character Entities, transforming ASCII email addresses into their equivalent decimal entities. * type: `boolean` * default value: `false` * introduced in: `1.6.1` === "input" ``` ``` === "output (value is `false`)" ```html myself@example.com ``` === "output (value is `true`)" ```html myself@example.com ``` ### excludeTrailingPunctuationFromURLs Exclude trailing punctuation from autolinked URLs: `.` `!` `?` `(` `)` This option applies only to links generated by [`simplifiedAutoLink`](#simplifiedautolink). * type: `boolean` * default value: `false` * introduced in: `1.5.1` === "input" ``` check this link www.google.com. ``` === "output (value is `false`)" ```html

check this link www.google.com.

``` === "output (value is `true`)" ```html

check this link www.google.com.

``` ### ghCodeBlocks Enable support for GFM code block style syntax (fenced codeblocks). * type: `boolean` * default value: `true` * introduced in: `0.3.1` === "example" ``` ``` some code here ``` ``` ### ghCompatibleHeaderId Generate heading IDs compatible with GitHub style: spaces are replaced with dashes, and certain non-alphanumeric chars are removed. !!! warning "" This option can be overridden with the [`noHeaderId`](#noheaderid) option. * type: `boolean` * default value: `false` * introduced in: `1.5.5` === "input" ``` # This is a heading with @#$% ``` === "output (value is `false`)" ```html

This is a heading

``` === "output (value is `true`)" ```html

This is a heading with @#$%

``` ### ghMentions Enables support for GitHub `@mentions` that allows you to link to the GitHub profile page of the mentioned username. * type: `boolean` * default value: `false` * introduced in: `1.6.0` === "input" ``` hello there @tivie ``` === "output (value is `false`)" ```html

hello there @tivie

``` === "output (value is `true`)" ```html

hello there @tivie

``` ### ghMentionsLink Specify where the link generated by `@mentions` should point to. Works only when [`ghMentions: true`](#ghmentions). * type: `boolean` * default value: `https://github.com/{u}` * introduced in: `1.6.2` === "input" ``` hello there @tivie ``` === "output (value is `https://github.com/{u}`)" ```html

hello there @tivie

``` === "output (value is `http://mysite.com/{u}/profile`)" ```html

hello there @tivie

``` ### headerLevelStart Set starting level for the heading tags. * type: `integer` * default value: `1` * introduced in: `1.1.0` === "input" ``` # This is a heading ``` === "output (value is `1`)" ```html

This is a heading

``` === "output (value is `3`)" ```html

This is a heading

``` ### literalMidWordUnderscores Treat underscores in the middle of words as literal characters. Underscores allow you to specify the words that should be emphasized. However, in some cases, this may be unwanted behavior. With this option enabled, underscores in the middle of words will no longer be interpreted as `` and ``, but as literal underscores. * type: `boolean` * default value: `false` * introduced in: `1.2.0` === "input" ``` some text with__underscores__in the middle ``` === "output (value is `false`)" ```html

some text withunderscoresin the middle

``` === "output (value is `true`)" ```html

some text with__underscores__in the middle

``` ### metadata Enable support for document metadata (front-matter). You can define metadata at the top of a document between `««« »»»` or `--- ---` symbols. * type: `boolean` * default value: `false` * introduced in: `1.8.5` === "input" ```js let ref = `referenced value`; var markdown = ` --- first: Lorem second: Ipsum ref_variable: ${ref} --- ` var conv = new showdown.Converter({metadata: true}); var html = conv.makeHtml(markdown); var metadata = conv.getMetadata(); ``` === "output (value is `true`)" ```js // console.log(metadata) { first: 'Lorem', second: 'Ipsum', ref_variable: 'referenced value' } ``` ### noHeaderId Disable automatic generation of heading IDs. !!! warning "" Setting the option to `true` overrides the following options: * [`prefixHeaderId`](#prefixheaderid) * [`customizedHeaderId`](#customizedheaderid) * [`ghCompatibleHeaderId`](#ghcompatibleheaderid) * type: `boolean` * default value: `false` * introduced in: `1.1.0` === "input" ``` # This is a heading ``` === "output (value is `false`)" ```html

This is a heading

``` === "output (value is `true`)" ```html

This is a heading

``` ### omitExtraWLInCodeBlocks Omit trailing newline in code blocks (which is set by default before the closing tag). This option affects both indented and fenced (gfm style) code blocks. * type: `boolean` * default value: `false` * introduced in: `1.0.0` === "input" ``` var foo = 'bar'; ``` === "output (value is `false`)" ```html
var foo = 'bar';
    
``` === "output (value is `true`)" ```html
var foo = 'bar';
``` ### openLinksInNewWindow Open links in new windows. * type: `boolean` * default value: `false` * introduced in: `1.7.0` === "input" ``` [link](https://google.com) ``` === "output (value is `false`)" ```html link ``` === "output (value is `true`)" ```html link ``` ### parseImgDimensions Set image dimensions from within Markdown syntax. * type: `boolean` * default value: `false` * introduced in: `1.1.0` === "example" ``` ![foo](foo.jpg =100x80) set width to 100px and height to 80px ![bar](bar.jpg =100x*) set width to 100px and height to "auto" ![baz](baz.jpg =80%x5em) set width to 80% and height to 5em ``` ### prefixHeaderId Add a prefix to the generated heading ID: * Passing a string will add that string to the heading ID. * Passing `true` will add a generic `section` prefix. !!! warning "" This option can be overridden with the [`noHeaderId`](#noheaderid) option. * type: `string / boolean` * default value: `false` === "input" ``` # This is a heading ``` === "output (value is `false`)" ```html

This is a heading

``` === "output (value is `true`)" ```html

This is a heading

``` === "output (value is `showdown`)" ```html

This is a heading

``` ### rawHeaderId Replace ` ` (space), `'` (single quote), and `"` (double quote) with `-` (dash) in the generated heading IDs, including prefixes. !!! danger "" **Use with caution** as it might result in malformed IDs. * type: * default value: * introduced in: `1.7.3` ### rawPrefixHeaderId Prevent Showndown from modifying the prefix. Works only when [`prefixHeaderId`](#prefixheaderid) is set to a string value. !!! danger "" **Use with caution** as it might result in malformed IDs. For example, when the prefix contains special characters like `"` `\` `/` or others. * type: `boolean` * default value: `false` * introduced in: `1.7.3` ### requireSpaceBeforeHeadingText Require a space between a heading `#` and the heading text. * type: `boolean` * default value: `false` * introduced in: `1.5.3` === "input" ``` #heading ``` === "output (value is `false`)" ```html

heading

``` === "output (value is `true`)" ```html

#heading

``` ### simpleLineBreaks Parse line breaks as `
` in paragraphs (GitHub-style behavior). * type: `boolean` * default value: `false` * introduced in: `1.5.1` === "input" ``` a line wrapped in two ``` === "output (value is `false`)" ```html

a line wrapped in two

``` === "output (value is `true`)" ```html

a line
wrapped in two

``` ### simplifiedAutoLink Enable automatic linking for plain text URLs. * type: `boolean` * default value: `false` * introduced in: `1.2.0` === "input" ``` Lorem ipsum www.google.com ``` === "output (value is `false`)" ```html

Lorem ipsum www.google.com

``` === "output (value is `true`)" ```html

Lorem ipsum www.google.com

``` ### smartIndentationFix Resolve indentation problems related to ES6 template strings in the midst of indented code. * type: `boolean` * default value: `false` * introduced in: `1.4.2` ### smoothLivePreview Resolve an awkward effect when a paragraph is followed by a list. This effect appears on some circumstances, in live preview editors. * type: `boolean` * default value: `false` * introduced in: `1.2.1` !!! example "awkward effect" ![](http://i.imgur.com/YQ9iHTL.gif​) ### splitAdjacentBlockquotes Split adjacent blockquote blocks. * type: `boolean` * default value: `false` * introduced in: `1.8.6` === "input" ``` > Quote #1 >> Sub-quote 1 > Quote #2 >> Sub-quote 2 ``` === "output (value is `false`)" ```html

Quote #1

Sub-quote 1

Quote #2

Sub-quote 2

``` === "output (value is `true`)" ```html

Quote #1

Sub-quote 1

Quote #2

Sub-quote 2

``` ### strikethrough Enable support for strikethrough (``). * type: `boolean` * default value: `false` * introduced in: `1.2.0` === "input" ``` ~~strikethrough~~ ``` === "output (value is `true`)" ```html strikethrough ``` ### tables Enable support for tables syntax. * type: `boolean` * default value: `false` * introduced in: `1.2.0` === "example" ``` | h1 | h2 | h3 | |:------|:-------:|--------:| | 100 | [a][1] | ![b][2] | | *foo* | **bar** | ~~baz~~ | ``` ### tablesHeaderId Generate automatic IDs for table headings. Works only when [`tables: true`](#tables). * type: `boolean` * default value: `false` * introduced in: `1.2.0` ### tasklists Enable support for GitHub style tasklists. * type: `boolean` * default value: `false` * introduced in: `1.2.0` === "example" ``` - [x] This task is done - [ ] This task is still pending ``` ### underline Enable support for underline. If enabled, underscores will no longer be parsed as `` and ``. * type: `boolean` * default value: `false` * status: `Experimental` === "example" ``` __underlined word__ // double underscores ___underlined word___ // triple underscores ```