Parsedown vs Showdown
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
A Markdown-to-HTML parser for PHP, packaged as a single file with no dependencies.
Open source · MIT
A JavaScript library that converts Markdown to HTML and HTML back to Markdown.
The short answer
Choose Parsedown if you need…
- PHP developers who need to render Markdown inside a PHP web application
- Projects that want a small parser with no external dependencies
- Sites that display user-written Markdown and can enable its safe mode
- Developers who want to extend the parser with their own syntax
Choose Showdown if you need…
- JavaScript developers adding Markdown rendering to a web page
- Node.js developers converting Markdown files on a server
- Projects that need two-way conversion between HTML and Markdown
- Developers who want options such as tables, header ids, or image sizing
Side-by-side
| Parsedown | Showdown | |
|---|---|---|
| Type | Library | Library |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 15k | 14.9k |
| Setup difficulty | Beginner | Beginner |
| How you get it | Install with a package manager | Install with a package manager |
| Main language | PHP | JavaScript |
| Last code update | 9 months ago | 8 days ago |
What each one is
Parsedown
Parsedown is a PHP library that converts Markdown text into HTML. Markdown is a simple plain-text format for headings, lists, links and emphasis. Developers use Parsedown to show formatted text on websites, such as user comments or content pages, without writing HTML by hand.
Showdown
Showdown is a JavaScript library that turns Markdown text (a simple plain-text formatting syntax) into HTML, and can also convert HTML back into Markdown. It runs in a web browser or on a server with Node.js. Developers use it to let people write formatted text in a simple syntax and display it as web pages.
Best for
Parsedown
- PHP developers who need to render Markdown inside a PHP web application
- Projects that want a small parser with no external dependencies
- Sites that display user-written Markdown and can enable its safe mode
- Developers who want to extend the parser with their own syntax
Showdown
- JavaScript developers adding Markdown rendering to a web page
- Node.js developers converting Markdown files on a server
- Projects that need two-way conversion between HTML and Markdown
- Developers who want options such as tables, header ids, or image sizing
Strengths
Parsedown
- Ships as one file with no dependencies, so it is simple to include
- The README lists security options, including safe mode and escaping HTML, for untrusted input
- Installable via Composer or by downloading a single file, with MIT licensing
Showdown
- Works both in the browser and on Node.js
- Options let you adjust output such as header ids, header levels, and links
- Released under the MIT license
Not ideal for
Parsedown
- Non-PHP projects, since the library is written only for PHP
- Teams that need full CommonMark compliance, because the README says it passes most but not all CommonMark tests
- Anyone who wants a finished end-user app rather than code to integrate
Showdown
- People who just want to write Markdown in a ready-made editor app, since this is a library, not an app
- Projects that need the exact GitHub rendering behavior, since the README mentions GitHub-style ids but does not claim full compatibility
- Anyone needing current browser support for very old browsers, since the README lists tested versions from decades ago without current testing details
Trade-offs
Parsedown
- The README says it passes most CommonMark tests but not all, so output may differ from other CommonMark tools
- The README warns that the markup-escaping option is not safe from XSS and that extensions need their own safety review
- The README describes the release only as 1.8.0 and gives no detailed changelog, so update details are unclear
Showdown
- The README is a long list of options and does not document every edge case, so you may need the wiki for detail
- The browser compatibility section lists very old browsers and gives no current test results
- Some features such as tables are off by default and must be turned on
Getting started
Parsedown
Install with Composer
composer require erusev/parsedownFrequently asked questions
What is the difference between Parsedown and Showdown?
Parsedown: A Markdown-to-HTML parser for PHP, packaged as a single file with no dependencies. Showdown: A JavaScript library that converts Markdown to HTML and HTML back to Markdown. Parsedown suits php developers who need to render markdown inside a php web application, while Showdown suits javascript developers adding markdown rendering to a web page.
Are Parsedown and Showdown free?
Parsedown: Free and open source. Showdown: Free and open source.
Is Parsedown or Showdown more popular?
Parsedown has more GitHub stars (15k) than Showdown (14.9k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to Parsedown and Showdown?
Other options people compare them with include markdown-it, remark, Turndown, react-markdown, Editor.md.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.