The free online Markdown to HTML converter turns Markdown into clean, semantic HTML with a live preview, covering CommonMark and GitHub Flavored Markdown. Because it runs in the browser, the text is never uploaded.
Markdown tools by OnlinePCApps since 2013
A browser reads HTML, not the hash marks and asterisks of Markdown. The free online converter turns Markdown into the clean HTML a page, a CMS or an email needs, with a live preview alongside.
A README, a note or a piece of documentation written in Markdown has to become HTML before a page or a CMS can show it. Converting it produces the semantic markup, headings, lists and code, ready to drop into a site.
Guessing how a table or a nested list will look is slow and error-prone. A live preview shows the rendered result beside the source, so a heading level or a broken list is caught the moment the Markdown is written.
A heading becomes a heading tag, a list becomes a list and a code fence becomes a code block, rather than a wall of divs. That clean, semantic markup is easy to style with CSS and reads well to a browser and a screen reader alike.
Paste the Markdown into the panel above, or drop a .md file. A README, a set of release notes, a blog draft or any Markdown text works as input, read on the device.
The HTML appears as the Markdown is typed, with a live preview of how it renders. GitHub Flavored Markdown is on, so a table, a task list or a fenced code block converts the same way it does on GitHub.
Copy the HTML to the clipboard, or download it as a file, ready to drop into a page or a template. The Markdown stays untouched, so it can be edited and converted again at any time.
To convert Markdown is to turn its plain-text marks into semantic HTML. The tool handles that in the browser.
The parser follows CommonMark, the strict spec that makes the output predictable, then layers GitHub Flavored Markdown on top. That adds pipe tables, task lists, strikethrough and autolinks, so a document renders the same way it does on GitHub.
The rendered page shows next to the HTML source as the Markdown is typed, so the effect of each change is visible at once. That turns writing Markdown into a quick loop of edit and see, rather than a guess at the result.
A fenced code block with a language after the backticks becomes a code block with syntax highlighting, so a tutorial or a README reads clearly. Inline code and blockquotes carry across into their own tags as well.
The HTML copies with one click, ready for a page or a template. Markdown allows raw HTML, so output from an untrusted source should be run through a sanitiser before it is shown, a point covered below.
To convert Markdown to HTML, to turn a README into markup and to preview GFM all name the same tool. A search for Markdown to HTML or md to HTML reaches this page, and the Markdown is left as it is.
Markdown is a plain-text syntax that maps to HTML. These points decide how the result renders.
| The case | Result | What happens and why |
|---|---|---|
| Headings | # to ###### | Hash marks become the heading tags from h1 down to h6. |
| Emphasis | bold, italic | Double and single markers become strong and emphasis tags. |
| Lists and links | clean tags | Bulleted and numbered lists, links and images map to their tags. |
| Fenced code | highlighted | Triple backticks with a language become a highlighted code block. |
| GFM tables | pipe rows | Pipe-separated rows become a real HTML table. |
| Task lists | - [x] | Checkbox items render as task list boxes, a GitHub extension. |
| CommonMark | the spec | The strict standard that makes the output predictable across parsers. |
| Raw HTML | sanitise it | Markdown allows HTML, so untrusted output must be sanitised first. |
| Where it runs | on the device | The Markdown is converted in the browser, so nothing is uploaded. |
How Markdown Becomes HTML
Markdown is a plain-text way of writing formatted documents, created by John Gruber in 2004, where a hash marks a heading, asterisks mark emphasis and triple backticks mark a code block. A browser does not read those marks, so a converter turns them into HTML first, the tags a browser actually shows. It works in two steps: the parser reads the source and builds a tree of nodes, a heading here, a list there, then walks that tree and writes the matching semantic tags, an h1, a strong, a pre and code. Two standards shape the result. CommonMark is the strict spec that pins down the many places Gruber left ambiguous, so a compliant parser gives the same output every time. GitHub Flavored Markdown sits on top of it, adding pipe tables, task lists, strikethrough and autolinks. The one honest point that matters most is safety. Markdown lets raw HTML through on purpose, so a document can carry a script tag or an event handler, a cross-site scripting or XSS risk, which means output built from untrusted input has to be run through a sanitiser such as DOMPurify before it is placed on a page. Converting text that belongs to the writer, previewed locally, has no such risk. The references below define the standards.
Both turn Markdown into HTML. The trade is between a quick copy and a full build with layouts.
| Point of comparison | This tool Converted in the browser On the device | A site generator A local build tool |
|---|---|---|
| Where the text goes | Stays in the browser | Runs on the machine |
| Price and caps | Free with no file cap | Free tier often capped |
| A whole site with layouts | One document at a time | Folders wrapped in templates |
| Part of a build | A manual copy here | Hugo or Eleventy in a pipeline |
| A quick preview and copy | Paste, preview, copy | A project to set up |
A static site generator such as Hugo or Eleventy wins for a whole site of Markdown wrapped in templates and built as part of a pipeline. This page wins for a quick convert of one document with a live preview and no project to set up. Both run the parser locally.
The Markdown is parsed and rendered inside the browser by a client-side parser, so the work stays on the machine that opened it. Nothing is handed to a server to run the conversion or the preview.
The Markdown being converted is often a private README, a set of unpublished release notes or a client document not cleared for an outside server. A hosted converter would take all of it on upload, needless exposure when the browser can do the job locally.
Each of these turns Markdown into HTML. They vary in reach, in effort and in where the text goes.
A site generator, a library, an editor and Pandoc all convert Markdown, yet each means a project, a script or the terminal. This page converts one document with a live preview and the HTML source, kept local with nothing to set up.
A little context sets a safer conversion.
Markdown allows raw HTML, so a document from a stranger can carry a script tag. Before showing HTML built from untrusted input on a live page, run it through a sanitiser such as DOMPurify. Text of the writer's own, previewed here, is safe.
CommonMark is the strict base, and GitHub Flavored Markdown adds tables, task lists and strikethrough on top. A table or a checkbox needs GFM, so a document that uses them should be converted with the GFM extensions on.
Markdown to HTML is clean, since Markdown is a subset that maps neatly to tags. The reverse, HTML to Markdown, is lossy, because HTML holds far more than Markdown can express, so a round trip is not always identical.
The browser converts one document with a live preview, which suits a quick job. A whole folder of Markdown wrapped in layouts, or a build that runs on every commit, belongs on a static site generator such as Hugo or Eleventy, which reads from disk and builds the whole site.
A generator wraps each Markdown page in a shared layout and a theme, so a whole site looks consistent without repeating the markup.
A build turns the Markdown into a full site each time the source changes, so the published pages stay in step with the writing.
A generator builds a menu, a table of contents and cross-links across pages, the parts a single conversion cannot know about.
Free and online, with no sign-up and no upload. Turn Markdown into clean HTML in the browser, all on the device.