Showdown is a JavaScript Markdown to HTML converter, based on the original works by John Gruber. It allows you to easily convert Markdown text into HTML, making it useful for web applications, documentation, and other text processing tasks.
Convert Markdown to HTML
This feature allows you to convert Markdown text into HTML. The code sample demonstrates how to create a new Showdown converter instance and use it to convert a Markdown string into HTML.
const showdown = require('showdown');
const converter = new showdown.Converter();
const markdown = '# Hello, Showdown!';
const html = converter.makeHtml(markdown);
console.log(html);Customize Output
Showdown allows you to customize the output by enabling or disabling various options. The code sample shows how to enable the 'tables' and 'strikethrough' options to enhance the Markdown to HTML conversion.
const showdown = require('showdown');
const converter = new showdown.Converter({ tables: true, strikethrough: true });
const markdown = '~~Strikethrough~~ and a table:
| h1 | h2 |
| --- | --- |
| cell1 | cell2 |';
const html = converter.makeHtml(markdown);
console.log(html);Extension Support
Showdown supports extensions, allowing you to add custom functionality to the conversion process. The code sample demonstrates how to create a simple extension that converts '@text' into bold HTML text.
const showdown = require('showdown');
showdown.extension('myextension', function() {
return [{
type: 'lang',
regex: /@( ext)/g,
replace: '<strong>$1</strong>'
}];
});
const converter = new showdown.Converter({ extensions: ['myextension'] });
const markdown = 'This is @text.';
const html = converter.makeHtml(markdown);
console.log(html);Marked is a fast, lightweight Markdown parser and compiler. It is designed for speed and offers a high level of customization. Compared to Showdown, Marked is often preferred for its performance and flexibility in handling large Markdown files.
Markdown-it is a powerful Markdown parser that offers a wide range of features, including plugins and high-speed performance. It is known for its extensibility and ability to handle complex Markdown syntax. Markdown-it provides more advanced features and customization options compared to Showdown.
Remark is a Markdown processor powered by plugins. It is part of the unified collective and offers a highly modular and extensible approach to Markdown processing. Remark is suitable for users who need a highly customizable and plugin-based solution, whereas Showdown is more straightforward and easier to use out of the box.
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).
You can download the latest release tarball directly from https://github.com/showdownjs/showdown/releases
bower install showdown
npm install showdown
You can also use github CDN directly in your html file(s).
https://cdn.rawgit.com/showdownjs/showdown/<version tag>/dist/showdown.min.js
You can check the full changelog at https://github.com/showdownjs/showdown/blob/master/CHANGELOG.md
Showdown has been tested successfully with:
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.
Showdown has been tested with node 0.8 and 0.10. However, it should work with previous versions, such as node 0.6.
If you're looking for showdown v<1.0.0, you can find it in the legacy branch.
var showdown = require('showdown'),
converter = new showdown.Converter(),
text = '#hello, markdown!',
html = converter.makeHtml(text);
var converter = new showdown.Converter(),
text = '#hello, markdown!',
html = converter.makeHtml(text);
Both examples should output...
<h1 id="hellomarkdown">hello, markdown!</h1>
You can change some of showdown's default behavior through options.
Options can be set:
Setting a "global" option affects all instances of showdown
showdown.setOption('optionKey', 'value');
Setting a "local" option only affects the specified Converter object. Local options can be set:
through the constructor
var converter = new showdown.Converter({optionKey: 'value');
through the setOption() method
var converter = new showdown.Converter();
conveter.setOption('optionKey', 'value');
Showdown provides 2 methods (both local and global) to retrieve previous set options.
// Global
var myOption = showdown.getOption('optionKey');
//Local
var myOption = converter.getOption('optionKey');
// Global
var showdownGlobalOptions = showdown.getOptions();
//Local
var thisConverterSpecificOptions = conveter.getOptions();
You can get showdown's default options with:
var defaultOptions = showdown.getDefaultOptions();
omitExtraWLInCodeBlocks: (boolean) [default false] Omit the trailing newline in a code block. Ex:
This:
<code><pre>var foo = 'bar';
</pre></code>
Becomes this:
<code><pre>var foo = 'bar';</pre></code>
noHeaderId: (boolean) [default false] Disable the automatic generation of header ids. Setting to true overrides prefixHeaderId
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.
parseImgDimensions: (boolean) [default false] Enable support for setting image dimensions from within markdown syntax. Example:
headerLevelStart: (integer) [default 1] Set the header starting level. For instance, setting this to 3 means that
# foo will be parsed as <h3>foo</h3>
ShowdownJS project also provides seamlessly integration with AngularJS via a "plugin". Please visit https://github.com/showdownjs/ngShowdown for more information.
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) for more information.
Showdown allows additional functionality to be loaded via extensions. (you can find a list of known showdown extensions here)
<script src="showdown.js" />
<script src="twitter-extension.js" />
var converter = new showdown.Converter({ extensions: 'twitter' });
var showdown = require('showdown'),
myExtension = require('myExtension'),
converter = new showdown.Converter({ extensions: ['myExtension'] });
A suite of tests is available which require node.js. Once node is installed, run the following command from the project root to install the development dependencies:
npm install --dev
Once installed the tests can be run from the project root using:
npm test
New test cases can easily be added. Create a markdown file (ending in .md) which contains the markdown to test. Create a .html file of the exact same name. It will automatically be tested when the tests are executed with mocha.
If you wish to contribute please read the following quick guide.
You can request a new feature by submitting an issue. If you would like to implement a new feature feel free to issue a Pull Request.
PRs are awesome. However, before you submit your pull request consider the following guidelines:
Search GitHub for an open or closed Pull Request that relates to your submission. You don't want to duplicate effort.
When issuing PRs that change code, make your changes in a new git branch based on master:
git checkout -b my-fix-branch master
Documentation (i.e: README.md) changes can be made directly against master.
Run the full test suite before submitting and make sure all tests pass (obviously =P).
Try to follow our coding style rules. Breaking them prevents the PR to pass the tests.
Refrain from fixing multiple issues in the same pull request. It's preferable to open multiple small PRs instead of one hard to review big one.
If the PR introduces a new feature or fixes an issue, please add the appropriate test case.
We use commit notes to generate the changelog. It's extremely helpful if your commit messages adhere to the AngularJS Git Commit Guidelines.
If we suggest changes then:
git rebase master -i
git push origin my-fix-branch -f
After your pull request is merged, you can safely delete your branch.
If you have time to contribute to this project, we feel obliged that you get credit for it. These rules enable us to review your PR faster and will give you appropriate credit in your GitHub profile. We thank you in advance for your contribution!
We're looking for members to help maintaining Showdown. Please see this issue to express interest or comment on this note.
Full credit list at https://github.com/showdownjs/showdown/blob/master/CREDITS.md
Showdown is powered by:
1.1.0 (2015-06-18)
showdown.extensions property. To migrate, extensions should use the new method showdown.extension(<ext name>, <extension>) to register.
For more information on the new extension loading mechanism, please check the wiki pages.
(4ebd0caa)<a name"1.0.2"></a>
FAQs
A Markdown to HTML converter written in Javascript
We found that showdown demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 2 open source maintainers collaborating on the project.
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