Two languages for writing structured text on the web. One is the sketch; the other is the blueprint. Picking between them is mostly a question of how much control you need — and how much typing you’re willing to do to get it.
TL;DR
- Markdown is a plain-text shorthand for structured prose. It compiles to HTML.
- HTML is the markup language browsers actually render. It covers everything from headings to interactive widgets.
- Use markdown when:you’re writing prose, docs, READMEs, blog posts, or anything you’ll revise often.
- Use HTML when: you need custom classes, scripts, forms, accessibility attributes, or precise layout control.
- Use both when:you’re building a website — markdown for the content, HTML for the chrome around it.
- Markdown saves keystrokes. HTML saves you when markdown runs out of ways to say what you mean.
Markdown and HTML, defined
HTML (HyperText Markup Language) is the standard markup language for documents displayed in a web browser. It was created by Tim Berners-Lee in 1991 and is standardized by the W3C and WHATWG. HTML uses paired tags (<p>...</p>) to mark up content. Every page you’ve ever looked at in a browser is, underneath, HTML.
Markdown is a lightweight markup language created by John Gruber in 2004. It uses punctuation shortcuts (#, *, -, []()) to indicate structure. A markdown file is plain text — readable without any tool — and converts to HTML through a renderer like markdown-it, CommonMark, or Pandoc. See our full markdown explainer for the longer history.
The relationship is asymmetric: markdown is a strict subset of what HTML can express, and a markdown renderer’s job is to translate the subset into HTML the browser can render.
Markdown vs HTML at a glance
The differences are clearest in a side-by-side comparison. Same document, two languages.
| Dimension | Markdown | HTML |
|---|---|---|
| Year created | 2004 (John Gruber) | 1991 (Tim Berners-Lee) |
| Standard body | CommonMark, GFM (de facto) | W3C, WHATWG |
| File extension | .md, .markdown | .html, .htm |
| Ease of writing | Very fast — punctuation marks | Verbose — paired tags |
| Expressiveness | About 20% of HTML | Complete: layout, forms, scripts |
| Readability raw | Reads as clean plain text | Tags clutter the prose |
| Browser support | Renders only after compilation | Native, universal |
| Author audience | Writers, devs, AI models | Browsers, frameworks, devs |
| Heading | ## Section | <h2>Section</h2> |
| Bold | **bold** | <strong>bold</strong> |
| Link | [text](url) | <a href="url">text</a> |
| Image |  | <img src="src" alt="alt"> |
| List | - item | <ul><li>item</li></ul> |
| Custom classes | Not supported (need inline HTML) | Native |
| Forms / scripts / interactive | Not supported | Native — <form>, <script>, <button>, etc. |
| Accessibility (ARIA) | Not directly expressible | Native, full support |
| Used by | GitHub, Notion, ChatGPT, Slack, Discord | Every website on the web |
| Best for | Prose, docs, READMEs, blog posts | Pages, apps, layouts, custom components |
Markdown is the language you write in. HTML is the language the browser reads.
When to choose markdown
Markdown wins decisively in five situations.
- Long-form prose. Essays, blog posts, articles, documentation. The savings on closing tags compound into hours.
- READMEs and project docs. Markdown is the only format GitHub, GitLab, and the rest will render as the front page of your repo.
- AI-generated text. Every LLM emits markdown by default. If your loop involves an AI model, your content is already markdown.
- Frequent revision. Markdown diffs cleanly in git. HTML diffs are a wall of tag noise.
- Multi-format publishing. One
.mdfile can become PDF, DOCX, HTML, EPUB through Pandoc or mdclaudy. HTML locks you to the web.
When to choose HTML
HTML is the right choice when markdown runs out of vocabulary.
- Custom layout. Multi-column, grid, sidebars, callouts with specific styling. Markdown is structure-only; HTML owns presentation.
- Interactive elements.Forms, buttons, dropdowns, modals, dialogs. Markdown can’t express any of them.
- Accessibility.
aria-*attributes,roleattributes, screen-reader hints. HTML is the accessibility layer of the web. - Scripts and styling. Anything involving
<script>,<style>, orclass="...". Markdown was designed not to touch presentation, on purpose. - Email HTML.Email clients still want explicit table layouts and inline styles. Don’t bother with markdown for newsletters.
When to use both — the hybrid workflow
The dominant pattern in 2026 is to use both. The markdown is the source; the HTML is the artifact.
You write content in markdown. A site generator — Next.js, Astro, Hugo, Jekyll, Docusaurus, Mintlify — turns it into HTML at build time. The layout, components, navigation, and styling live in template files; the content lives in .md. When you want to change a sentence, you edit markdown. When you want to redesign the page, you edit templates. The two concerns never collide.
This pattern lets you escape-hatch into raw HTML inside a markdown file when you need to. CommonMark and GFM both allow inline HTML blocks. So when markdown can’t express something — <details>, a table with merged cells, a video embed — you drop the HTML straight in, and the renderer passes it through.
A note on SEO
Authors sometimes ask whether markdown is “worse for SEO.” It’s not. Search engines index the rendered HTML — the same HTML you’d hand-write. What matters for SEO is the HTML output: clean heading hierarchy, descriptive alt text, semantically correct elements, fast page load. Markdown produces all of those by default, often better than hand-written HTML, because the renderer enforces structure.
If you’re running a blog or documentation site, write in markdown and let the static site generator produce the HTML. The rendered output is identical to what you’d write by hand — minus the typos and the broken closing tags. Google indexes the result the same way.
Converting between the two
Both directions are well-supported.
Markdown to HTML
The standard JavaScript options are markdown-it, remark, and marked. In Python: mistune or markdown. The cross-platform reference tool is Pandoc: pandoc input.md -o output.html. For a one-shot browser-based conversion with no install, see our markdown-to-HTML guide with a live converter.
HTML to markdown
Use Turndown (JavaScript) or html2text (Python) or, again, Pandoc: pandoc input.html -o output.md. Anything HTML can express that markdown can’t — custom classes, scripts, inline styles — gets dropped, but the prose and basic structure round-trips cleanly.
In an AI context, markdown wins by default
One pattern worth naming explicitly: when an AI assistant is anywhere in the writing loop, markdown is effectively forced. Every major model — ChatGPT, Claude, Gemini, Llama — outputs markdown natively. Asking the model for HTML works but burns tokens on tags and tends to produce malformed output (unclosed tags, missing attributes). Asking for markdown gives you cleaner structure, faster.
This is why AI-native editors tend to be markdown-first. The format is what the model speaks. The HTML comes later, when you ship.
A decision matrix
Five questions. The answers tell you which to pick.
| Question | Choose |
|---|---|
| Am I writing prose? | Markdown |
| Do I need scripts or forms? | HTML |
| Will an AI write or edit this? | Markdown |
| Do I need precise visual layout? | HTML (or markdown with embedded HTML) |
| Will this live in git? | Markdown (diffs cleanly) |
| Is this an email? | HTML |
| Is this a README? | Markdown |
| Do I need ARIA attributes? | HTML |
| Am I publishing to PDF or DOCX too? | Markdown (one source, many outputs) |
A practical example: writing this blog post
This article is itself a hybrid. The prose was drafted in markdown. The page you’re reading is rendered React/HTML. The tables, the headings, the bullets — all of them started as markdown shorthand and ended as semantic HTML. The custom callouts and the conversion CTA are HTML components the markdown couldn’t express. Both languages cooperated. Neither tried to be the other.
For documents you intend to ship as something other than a webpage — a PDF, a Word file, an EPUB — the same logic applies. Write the source as markdown. Render it through a tool that respects the target format. mdclaudy is our take on that for PDF: fifteen designed templates sitting on top of a clean markdown editor.
Frequently asked questions
Keep reading
- What is markdown? — the fuller explainer, including the cheat sheet.
- Markdown to HTML— the developer’s complete guide, with a live converter.
- Markdown to PDF — the hub for every export route.
- Markdown tables — the bit of markdown most authors get wrong.
- The best markdown editors of 2026 — where to write your markdown in the first place.