![Showdown][sd-logo] ![Build Status: Linux](https://github.com/showdownjs/showdown/actions/workflows/node.linux.yml/badge.svg) ![Build Status: Windows](https://github.com/showdownjs/showdown/actions/workflows/node.win.yml/badge.svg) [![npm version](https://badge.fury.io/js/showdown.svg)](http://badge.fury.io/js/showdown) [![Bower version](https://badge.fury.io/bo/showdown.svg)](http://badge.fury.io/bo/showdown) [![Join the chat at https://gitter.im/showdownjs/showdown](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/showdownjs/showdown?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) [![Donate](https://img.shields.io/badge/Donate-PayPal-green.svg)](https://www.paypal.me/tiviesantos) ------ Showdown is a Javascript Markdown to HTML converter, based on the original works by John Gruber. Showdown can be used client side (in the browser) or server side (with NodeJs). ## Live DEMO Check a live Demo here http://demo.showdownjs.com/ As you know, ShowdownJS is a free library and it will remain free forever. However, maintaining and improving the library costs time and money. If you like our work and find our library useful, please donate through [paypal](https://www.paypal.me/tiviesantos)!! Your contribution will be greatly appreciated and help me continue to develop this awesome library. ## License ShowdownJS v 2.0 is release under the MIT version. Previous versions are release under BSD. ## Who uses Showdown (or a fork) - [GoogleCloudPlatform](https://github.com/GoogleCloudPlatform) - [Meteor](https://www.meteor.com/) - [Stackexchange](http://stackexchange.com/) - forked as [PageDown](https://code.google.com/p/pagedown/) - [docular](https://github.com/Vertafore/docular) - [md-page](https://github.com/oscarmorrison/md-page) - [QCObjects](https://qcobjects.dev) - [and some others...](https://www.npmjs.com/browse/depended/showdown) ## Installation ### Download tarball You can download the latest release tarball directly from [releases][releases] ### Bower bower install showdown ### npm (server-side) npm install showdown ### NuGet package PM> Install-Package showdownjs The NuGet Packages can be [found here](https://www.nuget.org/packages/showdownjs/). ### CDN You can also use one of several CDNs available: * jsDelivr https://cdn.jsdelivr.net/npm/showdown@/dist/showdown.min.js * cdnjs https://cdnjs.cloudflare.com/ajax/libs/showdown//showdown.min.js * unpkg https://unpkg.com/showdown/dist/showdown.min.js *Note*: replace `` with an actual full length version you're interested in e.g. `1.9.0` ## Browser Compatibility Showdown has been tested successfully with: * Firefox 1.5 and 2.0 * Chrome 12.0 * Internet Explorer 6 and 7 * Safari 2.0.4 * Opera 8.54 and 9.10 * Netscape 8.1.2 * Konqueror 3.5.4 In theory, Showdown will work in any browser that supports ECMA 262 3rd Edition (JavaScript 1.5). The converter itself might even work in things that aren't web browsers, like Acrobat. No promises. ## Node compatibility Showdown is intended to work on any supported node.js version (see the [node.js releases schedule](https://nodejs.org/en/about/releases/). The code may work with previous versions of node.js, but no accomidations are made to ensure it does. ## Legacy version If you're looking for showdown v<1.0.0, you can find it in the [**legacy branch**][legacy-branch]. ## Changelog You can check the full [changelog][changelog] ## Extended documentation Check our [wiki pages][wiki] for examples and a more in-depth documentation. ## Quick Example ### Node ```js var showdown = require('showdown'), converter = new showdown.Converter(), text = '# hello, markdown!', html = converter.makeHtml(text); ``` ### Browser ```js var converter = new showdown.Converter(), text = '# hello, markdown!', html = converter.makeHtml(text); ``` ### Output Both examples should output... ```html

hello, markdown!

``` ## Options You can change some of showdown's default behavior through options. ### Setting options Options can be set: #### Globally Setting a "global" option affects all instances of showdown ```js showdown.setOption('optionKey', 'value'); ``` #### Locally Setting a "local" option only affects the specified Converter object. Local options can be set: * **through the constructor** ```js var converter = new showdown.Converter({optionKey: 'value'}); ``` * **through the setOption() method** ```js var converter = new showdown.Converter(); converter.setOption('optionKey', 'value'); ``` ### Getting an option Showdown provides 2 methods (both local and global) to retrieve previous set options. #### getOption() ```js // Global var myOption = showdown.getOption('optionKey'); //Local var myOption = converter.getOption('optionKey'); ``` #### getOptions() ```js // Global var showdownGlobalOptions = showdown.getOptions(); //Local var thisConverterSpecificOptions = converter.getOptions(); ``` ### Retrieve the default options You can get showdown's default options with: ```js var defaultOptions = showdown.getDefaultOptions(); ``` ### Valid Options * **omitExtraWLInCodeBlocks**: (boolean) [default false] Omit the trailing newline in a code block. Ex: This: ```html
var foo = 'bar';
    
``` Becomes this: ```html
var foo = 'bar';
``` * **noHeaderId**: (boolean) [default false] Disable the automatic generation of header ids. Setting to true overrides **prefixHeaderId** * **customizedHeaderId**: (boolean) [default false] Use text in curly braces as header id. **(since v1.7.0)** Example: ``` ## Sample header {real-id} will use real-id as id ``` * **ghCompatibleHeaderId**: (boolean) [default false] Generate header ids compatible with github style (spaces are replaced with dashes and a bunch of non alphanumeric chars are removed) **(since v1.5.5)** * **prefixHeaderId**: (string/boolean) [default false] Add a prefix to the generated header ids. Passing a string will prefix that string to the header id. Setting to `true` will add a generic 'section' prefix. * **rawPrefixHeaderId**: (boolean) [default false] Setting this option to true will prevent showdown from modifying the prefix. This might result in malformed IDs (if, for instance, the " char is used in the prefix). Has no effect if prefixHeaderId is set to false. **(since v 1.7.3)** * **rawHeaderId**: (boolean) [default false] Remove only spaces, ' and " from generated header ids (including prefixes), replacing them with dashes (-). WARNING: This might result in malformed ids **(since v1.7.3)** * **headerLevelStart**: (integer) [default 1] Set the header starting level. For instance, setting this to 3 means that ```md # foo ``` will be parsed as ```html

foo

``` * **parseImgDimensions**: (boolean) [default false] Enable support for setting image dimensions from within markdown syntax. Examples: ``` ![foo](foo.jpg =100x80) simple, assumes units are in px ![bar](bar.jpg =100x*) sets the height to "auto" ![baz](baz.jpg =80%x5em) Image with width of 80% and height of 5em ``` * **simplifiedAutoLink**: (boolean) [default false] Turning this option on will enable automatic linking to urls. This means that: ```md some text www.google.com ``` will be parsed as ```html

some text www.google.com ``` * ~~**excludeTrailingPunctuationFromURLs**: (boolean) [default false] This option excludes trailing punctuation from autolinking urls. Punctuation excluded: `. ! ? ( )`. Only applies if **simplifiedAutoLink** option is set to `true`.~~ * **literalMidWordUnderscores**: (boolean) [default false] Turning this on will stop showdown from interpreting underscores in the middle of words as `` and `` and instead treat them as literal underscores. Example: ```md some text with__underscores__in middle ``` will be parsed as ```html

some text with__underscores__in middle

``` * ~~**literalMidWordAsterisks**: (boolean) [default false] Turning this on will stop showdown from interpreting asterisks in the middle of words as `` and `` and instead treat them as literal asterisks.~~ * **strikethrough**: (boolean) [default false] Enable support for strikethrough syntax. `~~strikethrough~~` as `strikethrough` * **tables**: (boolean) [default false] Enable support for tables syntax. Example: ```md | h1 | h2 | h3 | |:------|:-------:|--------:| | 100 | [a][1] | ![b][2] | | *foo* | **bar** | ~~baz~~ | ``` See the wiki for more info * **tablesHeaderId**: (boolean) [default false] If enabled adds an id property to table headers tags. * **ghCodeBlocks**: (boolean) [default true] Enable support for GFM code block style. * **tasklists**: (boolean) [default false] Enable support for GFM tasklists. Example: ```md - [x] This task is done - [ ] This is still pending ``` * **smoothLivePreview**: (boolean) [default false] Prevents weird effects in live previews due to incomplete input * **smartIndentationFix**: (boolean) [default false] Tries to smartly fix indentation problems related to es6 template strings in the midst of indented code. * **disableForced4SpacesIndentedSublists**: (boolean) [default false] Disables the requirement of indenting sublists by 4 spaces for them to be nested, effectively reverting to the old behavior where 2 or 3 spaces were enough. **(since v1.5.0)** * **simpleLineBreaks**: (boolean) [default false] Parses line breaks as `
`, without needing 2 spaces at the end of the line **(since v1.5.1)** ```md a line wrapped in two ``` turns into: ```html

a line
wrapped in two

``` * **requireSpaceBeforeHeadingText**: (boolean) [default false] Makes adding a space between `#` and the header text mandatory **(since v1.5.3)** * **ghMentions**: (boolean) [default false] Enables github @mentions, which link to the username mentioned **(since v1.6.0)** * **ghMentionsLink**: (string) [default `https://github.com/{u}`] Changes the link generated by @mentions. Showdown will replace `{u}` with the username. Only applies if ghMentions option is enabled. Example: `@tivie` with ghMentionsOption set to `//mysite.com/{u}/profile` will result in `@tivie` * **encodeEmails**: (boolean) [default true] Enable e-mail addresses encoding through the use of Character Entities, transforming ASCII e-mail addresses into its equivalent decimal entities. (since v1.6.1) NOTE: Prior to version 1.6.1, emails would always be obfuscated through dec and hex encoding. * **openLinksInNewWindow**: (boolean) [default false] Open all links in new windows (by adding the attribute `target="_blank"` to `` tags) **(since v1.7.0)** * **backslashEscapesHTMLTags**: (boolean) [default false] Support for HTML Tag escaping. ex: `\
foo\
` **(since v1.7.2)** * **emoji**: (boolean) [default false] Enable emoji support. Ex: `this is a :smile: emoji` For more info on available emojis, see https://github.com/showdownjs/showdown/wiki/Emojis **(since v.1.8.0)** * **underline**: (boolean) [default false] ***EXPERIMENTAL FEATURE*** Enable support for underline. Syntax is **double** or **triple** **underscores** ex: `__underlined word__`. With this option enabled, underscores are no longer parses into `` and ``. * **ellipsis**: (boolean) [default true] Replaces three dots with the ellipsis unicode character. * **completeHTMLDocument**: (boolean) [default false] Outputs a complete html document, including ``, `` and `` tags' instead of an HTML fragment. (since v.1.8.5) * **metadata**: (boolean) [default false] Enable support for document metadata (defined at the top of the document between `«««` and `»»»` or between `---` and `---`). (since v.1.8.5) ```js var conv = new showdown.Converter({metadata: true}); var html = conv.makeHtml(someMd); var metadata = conv.getMetadata(); // returns an object with the document metadata ``` * **splitAdjacentBlockquotes**: (boolean) [default false] Split adjacent blockquote blocks.(since v.1.8.6) * **moreStyling**: (boolean) [default false] Adds some useful classes for css styling. (since v2.0.1) - Tasklists: Adds the class `task-list-item-complete` to completed tasks items in GFM tasklists. **NOTE**: Please note that until **version 1.6.0**, all of these options are ***DISABLED*** by default in the cli tool. ## Flavors You can also use flavors or presets to set the correct options automatically, so that showdown behaves like popular markdown flavors. Currently, the following flavors are available: * original - original markdown flavor as in [John Gruber's spec](https://daringfireball.net/projects/markdown/) * vanilla - showdown base flavor (as from v1.3.1) * github - GFM (GitHub Flavored Markdown) ### Global ```javascript showdown.setFlavor('github'); ``` ### Instance ```javascript converter.setFlavor('github'); ``` ## CLI Tool Showdown also comes bundled with a Command Line Interface tool. You can check the [CLI wiki page][cli-wiki] for more info ## Integration with AngularJS ShowdownJS project also provides seamlessly integration with AngularJS via a "plugin". Please visit https://github.com/showdownjs/ngShowdown for more information. ## Integration with TypeScript If you're using TypeScript you maybe want to use the types from [DefinitelyTyped][definitely-typed] ## Integration with SystemJS/JSPM Integration with SystemJS can be obtained via the third party ["system-md" plugin](https://github.com/guybedford/system-md). ## Integration with VueJS To use ShowdownJS as a Vue component quickly, you can check [vue-showdown](https://vue-showdown.js.org/). ## XSS vulnerability Showdown doesn't sanitize the input. This is by design since markdown relies on it to allow certain features to be correctly parsed into HTML. This, however, means XSS injection is quite possible. Please refer to the wiki article [Markdown's XSS Vulnerability (and how to mitigate it)][xss-wiki] for more information. ## Extensions Showdown allows additional functionality to be loaded via extensions. (you can find a list of known showdown extensions [here][ext-wiki]) You can also find a boilerplate, to create your own extensions in [this repository][boilerplate-repo] ### Client-side Extension Usage ```js