Free Markdown to HTML converter

Markdown to HTML conversion is the operation in which a parser reads plain text carrying a small set of agreed marks and emits the equivalent HTML elements.

Markdown was designed with HTML as its target, so this is not an approximation between two unrelated formats. It is a substitution of a shorthand for the tags that shorthand was invented to stand for, and that origin is what makes the conversion predictable rather than interpretive. John Gruber released the first Markdown implementation in 2004, with syntax contributions from Aaron Swartz, and defined it as a text-to-HTML tool in its opening documentation.

A parser makes two passes over the document. The first pass resolves block level structure: paragraphs, headings, lists, blockquotes and code blocks. The second pass resolves the inline spans sitting inside those blocks: emphasis, links, images and code spans. That order decides the result whenever a piece of text can be read two ways. A hash character inside a fenced code block stays literal, because the block pass claimed the fence and its contents before the inline pass ran. An emphasis mark that opens in one paragraph and closes in the next produces no emphasis, because the block pass ended the first paragraph before anything looked for a closing mark.

The conversion is deterministic for everything the specification defines. Identical input produces identical HTML across conforming implementations, and the only room for variation sits in extensions, which each implementation enables or omits on its own terms. Current behaviour is governed by the CommonMark specification, maintained by John MacFarlane and the CommonMark group, whose 0.31.2 revision was published in 2024 and which fixed the ambiguities left open by the 2004 reference implementation.

The conversion produces no styling. It emits no fonts, no colours and no spacing rules, because markdown has no notation for any of them, and the HTML that comes back describes structure alone. What the parser returns is the output, and everything below refers to it by that name.

Which HTML tags does each Markdown element produce?

Markdown to HTML conversion covers 21 core elements, and each one maps to a fixed tag.

This table is the only place in this answer where markdown notation is written out; every later section names the marks in words instead. Keep the condition column in mind when a construct fails to convert, because a missing blank line and a missing space account for most of the cases where markdown reaches the output as literal text.

What is missing from the converted HTML?

The output is a fragment, not a complete web page. That fragment contains the elements listed above and nothing around them: no doctype declaration, no html, head or body wrapper, no stylesheet and no script.

This is exactly why a converted README opens in a browser as black serif text on white, looks nothing like the same file on the platform the reader is used to, and reads as a failed conversion when it is a correct one. GitHub, GitLab and Bitbucket each attach their own stylesheet to the fragment before displaying it; a bare fragment in a browser gets the browser’s default styles instead.

Two steps turn the fragment into a page that displays as intended. Wrap it in a doctype declaration and the html, head and body elements, then attach a stylesheet in the head. The tags the conversion emits are HTML5 elements, so an HTML5 doctype is the correct wrapper. You should attach a stylesheet before showing the page to anyone, since the difference between a fragment and a styled document is the whole of what readers judge.

Converting markdown to HTML online takes four steps, with no installation and no account. MarkdownToHTML.online accepts markdown pasted directly into the page and .md files, and hands back the HTML output alongside a rendered version of it.

1. Paste your markdown into the input area, or upload a .md file. The text now sits in the input area.
2. Read the output panel. The HTML has appeared there, updating as the input changes.
3. Press the copy button. The output is on the clipboard, ready for a template, a content manager or an editor.
4. Press the download button if you want the result as a file. An .html file has been saved to your machine.

Two behaviours look like errors and are not. A single line break inside a paragraph does not survive into the output, because the parser joins consecutive lines into one paragraph and separates paragraphs only at a blank line. Syntax the parser does not recognise is passed through as literal text rather than rejected, so an unsupported extension reaches the output as the characters you typed instead of as a tag.

You should read the rendered version before publishing, since a table with a mismatched row or a code fence left open shows up there immediately and in the output only on close inspection.

Where is your Markdown processed during conversion?

The conversion runs inside your own browser, on your own machine. MarkdownToHTML.online sends nothing to a server: the markdown is not uploaded, not stored and not readable by anyone else, and the page keeps converting once loaded even with the connection gone.

This matters for material that is not public yet. Unreleased documentation, a draft announcement and internal specifications stay on the machine they were written on, which is a different guarantee from a privacy policy promising that an uploaded file will be deleted later.

The rendered view is the same output displayed by the browser, not a second, separate version of the document. Opening a .md file in a text editor shows notation competing with prose; the rendered panel shows the document as its author meant it to be read, and no HTML has to be looked at to get there.

Four constructs account for most of the difference. A table in raw form is a grid of pipes and dashes that has to be counted column by column; rendered, it is a table with aligned cells and a distinct header row. A nested list in raw form is a stack of lines whose depth depends on counting leading spaces; rendered, indentation and bullet shape carry the hierarchy. A link in raw form buries the destination in brackets in the middle of the sentence; rendered, the sentence reads as a sentence and the destination sits behind the underlined text. A fenced code block in raw form is bounded by backtick lines that break the flow of the page; rendered, it is a monospaced block set apart from the prose around it.

The same panel shows how a piece of HTML displays, which makes it useful for checking a snippet before it goes into a page.

HTML written by hand inside a markdown document survives the conversion and reaches the output unchanged. The rule that decides this has two halves. Block level HTML passes through untouched, and everything inside it stops being parsed as markdown, so emphasis marks and list items written between an opening and closing div arrive in the output as literal characters. Inline HTML is preserved inside the surrounding paragraph, so a span, an abbr or a br in the middle of a sentence becomes part of that paragraph while the markdown around it continues to be parsed normally.

Two conditions determine the outcome. The opening tag of a block needs a blank line before it and the closing tag needs a blank line after it; without them, the parser treats the tags as inline content of a paragraph. The opening tag also has to sit at the start of the line or within three spaces of it, because four spaces of indentation turn the whole thing into an indented code block. When either condition fails, the reader sees the tags themselves on the page as visible text, escaped into entities, rather than the element they describe.

The opposite need has its own answer. To display tags rather than have them interpreted, place them inside a code span or a fenced code block, or precede the opening angle bracket with a backslash; each produces escaped entities in the output and visible tags on the page.

Some converters strip or sanitise raw HTML for safety, removing script elements, event handler attributes and iframes before emitting the output. MarkdownToHTML.online passes raw HTML through as written, which means what you type is what you get and any sanitising has to happen wherever the output is published.

Neither tables nor fenced code blocks come from the original markdown definition, and both arrive through extensions, which is where behaviour diverges. Both were standardised by the GitHub Flavored Markdown specification, published by GitHub in 2017 as a strict superset of CommonMark, and both are now supported widely enough that their absence is the exception.

A table is written with pipes separating cells and a row of dashes under the header defining it. Colons on that dash row set alignment: a colon on the left aligns left, a colon on the right aligns right, and colons on both sides centre the column. The conversion emits a <table> containing a <thead> with one <tr> of <th> cells and a <tbody> holding the remaining rows as <tr> elements of <td> cells, with alignment carried by an align attribute or a text-align style depending on the library. A row whose cell count does not match the header is not an error: excess cells are discarded, and missing cells are filled with empty ones, so a malformed row produces a short row rather than a broken table.

A fenced code block is opened and closed by a fence of three backticks or three tildes on their own lines, with an optional language identifier written immediately after the opening fence. The conversion emits a <pre> wrapping a <code>, and the language identifier lands in the class attribute of the <code> element in the form language-python. Colouring comes from a stylesheet and a highlighter such as Prism, highlight.js or Shiki reading that class, never from the conversion itself, so a code block that looks plain is behaving correctly.

MarkdownToHTML.online supports both extensions. As advice: check a converted table in the rendered panel before moving it into a content manager, since a dropped cell is visible there in a second and invisible in the output until the page is published.

Converting a file runs the identical conversion on identical rules; only the handling around it differs, in that the parser is handed the contents of a file instead of the contents of a text area and the result is saved instead of copied. No construct behaves differently because it arrived in a file.

In MarkdownToHTML.online, a single .md file is uploaded to the input area, converted on arrival, and downloaded as an .html file named after the source, so readme.md is saved as readme.html.

Relative paths are the part that breaks. Image references and links between documents are copied into the output exactly as written, so an image path pointing one folder up still points one folder up, resolved from wherever the HTML file now sits, and a link to another document still points at a .md file that no browser will render as a page. Two corrections are needed before the HTML moves into another folder or onto a server: rewrite the extensions in inter-document links from .md to .html, and either keep the converted file in the same folder as the original or update every image path to match its new location. If your images sit in a subfolder alongside the markdown and the HTML is saved beside them, no path change is required; if the HTML moves anywhere else, every relative reference has to be checked.

How do you convert several Markdown files at once?

Three practical routes convert several markdown files at once, and all of them run from a terminal.

Pandoc, written by John MacFarlane and available on macOS, Windows and Linux, converts a directory with a loop:

for f in *.md; do pandoc "$f" -o "${f%.md}.html"; done

marked, a JavaScript converter installed through npm and running anywhere Node.js runs, takes the same shape:

for f in *.md; do marked -i "$f" -o "${f%.md}.html"; done

Python-Markdown, installed through pip and running on macOS, Windows and Linux, keeps it identical:

for f in *.md; do markdown_py "$f" -f "${f%.md}.html"; done

Two things have to be decided before running a batch. The first is how the output files get named: mirroring the source names keeps inter-document links repairable with a single search and replace, while writing into a separate output directory keeps the source folder clean. The second is whether each document stays separate or all of them are merged into one, since Pandoc concatenates several inputs into a single output when they are passed together, which suits a handbook and ruins a set of independent pages.

Conversion in code is done by a parser library, and every mainstream language has at least one that is actively maintained.

One decision changes the result: which specification the library follows and which extensions it turns on by default. A library implementing CommonMark alone and a library implementing GitHub Flavored Markdown disagree on the same input in visible ways. A table becomes a paragraph of literal pipe characters instead of a <table>, a strikethrough pair stays on the page as tildes instead of becoming a <del>, a bare web address stays as text instead of becoming an <a>, and a single line break becomes a <br> under a hard-break setting that another library leaves off. Pinning the specification and listing the enabled extensions explicitly in configuration is what keeps two environments emitting the same HTML.

These libraries run in three places: a build step, where a static site generator converts every document once before deployment; a server, where a request converts stored markdown on the way out; and the browser, where the page converts text the reader has just typed. MarkdownToHTML.online does its conversion with a JavaScript parser running in the page.

Markdown exists to be written and read by people as plain text, and HTML exists to be interpreted by a browser and displayed. That difference of purpose, not syntax, is what separates them.

Four points decide which one a writer reaches for. Notation density is the first: markdown spends a character or two per construct, while HTML spends an opening and a closing tag on each. Raw readability is the second: a markdown file reads as prose in any text editor, while an HTML file interrupts every sentence with angle brackets. Expressive range is the third: HTML describes any structure a browser can render, including forms, media, semantic sections and arbitrary attributes, while markdown covers roughly the 21 constructs listed earlier and defers everything else to embedded HTML. Point of consumption is the fourth: markdown is consumed in editors, repositories and note applications, while HTML is consumed in browsers.

The asymmetry between them is what justifies converting at all. Markdown is written comfortably and HTML is published, so the traffic runs from markdown to HTML far more often than the other way. HTML is a markup language, introduced by Tim Berners-Lee at CERN in 1991; markdown is a lightweight markup language, released by John Gruber in 2004 with syntax contributions from Aaron Swartz.

Markdown to HTML is one pair among several that share the same parsing step and part company only at what gets emitted. A parser builds the same internal document tree whether the result will be HTML, PDF or DOCX, and the writer attached at the end determines the format that comes out.

The criterion that tells you which conversion you need is what the destination consumes, not what the source looks like. A browser consumes HTML, a print pipeline consumes PDF, an editorial workflow consumes DOCX, and a search index consumes plain text; the markdown on your disk is the same file in all four cases.

What can an HTML converter take as input?

A converter to HTML normally accepts markdown, plain text, DOCX, CSV, LaTeX and reStructuredText, and these inputs are not interchangeable. A converter is defined by its input side, because the output is HTML in every case, which is why tools are named after what they read.

Markdown brings something to the input side the alternatives do not: the structure is already marked in the text. A DOCX converter has to infer headings from style names, a CSV converter can only ever produce a table, and a plain text converter has nothing to infer from at all, while a markdown converter reads a structure its author declared explicitly.

MarkdownToHTML.online takes markdown pasted into the page and .md files. Web addresses and binary documents such as .docx and .pdf are not accepted.

How do you convert HTML back to Markdown?

The reverse conversion exists, through tools such as Turndown, html2text and Pandoc, and it loses information in a way the forward conversion does not. Markdown has no notation for most of what HTML expresses, so the reverse direction has to discard whatever it cannot represent.

What disappears on the way back is attributes, classes and inline styles, along with any element that has no markdown equivalent, including div, span, section, iframe and every table cell that spans more than one column. What survives is the text and the handful of constructs markdown can name.

The reverse conversion is still the right move in one situation: recovering the text of a published page in order to edit it as markdown, where the styling belongs to the site and only the words are wanted. MarkdownToHTML.online guarantees something the reverse cannot, which is that a given markdown input always produces the same HTML, whereas a given HTML input produces markdown that depends on which of its features the converter chose to drop.

How do you paste Markdown into a rich text editor with formatting?

Pasting markdown into a rich text editor with formatting works by converting it to HTML first and copying the rendered version rather than the code. The editor never sees markdown and never has to understand it; it receives formatted content on the clipboard and accepts it as its own.

The distinction between the two copy actions in MarkdownToHTML.online decides the outcome. Copying the output puts the HTML source on the clipboard as plain text, and the destination displays the tags themselves. Selecting the rendered panel and copying puts formatted content on the clipboard, and the destination displays headings, bold text and lists as formatting.

The destinations where this matters are word processors such as Microsoft Word, Google Docs and LibreOffice Writer, document editors such as Notion, Confluence and Coda, and mail composers such as Gmail, Outlook and Apple Mail. Headings, bold, italic, lists, links and tables survive the paste in all of them. Code block styling, class attributes and images referenced by a relative path do not, since the destination has no stylesheet to read the classes and no access to the folder the images sit in.

Which formats besides HTML can Markdown convert to?

Markdown converts to six destination formats in common use.

How do you convert Markdown to plain text?

Converting markdown to plain text strips the notation instead of translating it into anything. No tags are produced and no structure is recorded; the marks are simply removed.

What is kept is the words, the line breaks and the order of paragraphs and list items. What is lost is emphasis, heading levels, link destinations unless the converter appends them in brackets, images, and the boundaries of tables and code blocks. This is what you want when the text is going into a word count, a plain text email, a search index or a model prompt, where notation counts as noise.

How do you convert plain text to HTML?

Plain text carries no structure to convert, so something has to supply it before HTML can be produced. A converter given an unmarked text file can emit paragraphs at blank lines and nothing more, because there is no other signal in the file to act on.

Adding a handful of markdown marks to a plain text file is the shortest route to structured HTML. Three marks are enough to get from unstructured text to headings, paragraphs and lists in MarkdownToHTML.online: a hash and a space at the start of a line for a heading, a blank line between blocks for a paragraph, and a hyphen and a space at the start of a line for a list item.

Absolutely. MarkdownToHTML.online is ideal for converting README files, technical documentation, blog posts, notes, and other Markdown content into clean, structured HTML.

Developers, technical writers, bloggers, students, researchers, marketers, and content teams can all benefit from fast and reliable Markdown-to-HTML conversion.

Definitely. Converting Markdown to HTML makes it easier to publish content on websites, blogs, content management systems, email platforms, and documentation portals.

MarkdownToHTML.online prioritizes privacy and data security. Markdown conversion and edition runs entirely in your browser, so your content never needs to leave your device and is 100% secure.

Yes. MarkdownToHTML.online allows you to convert Markdown to HTML online for free, without installing software or creating an account.

Automated Markdown-to-HTML conversion is faster, more consistent, and less error-prone than manually writing HTML. It saves time while preserving headings, links, lists, tables, code blocks, and other formatting.

MarkdownToHTML.online offers instant conversion, clean HTML output, live rendering, support for common Markdown syntax, secure processing, and an easy-to-use interface.