Two tools for two jobs
Markdown is a lightweight syntax for writing formatted text with plain characters — # for headings, * for emphasis. HTML is the full markup language browsers actually render. Markdown is designed to be converted into HTML.
When Markdown is the right choice
- Writing content: blog posts, README files, documentation, notes — anywhere you want to focus on words, not tags.
- Readability in raw form: Markdown looks clean even before rendering.
- Speed: far less typing than HTML for the same result.
When you need HTML
- Precise layout and styling: Markdown can't express complex structure or classes.
- Interactive elements, forms, semantic attributes.
- Anything a browser must render directly without a conversion step.
They work together
Most Markdown supports inline HTML, so you can drop a raw HTML block into a Markdown document when you need something Markdown can't express. Static site generators and many CMSs take Markdown in and produce HTML out — giving you the writing speed of one and the rendering of the other.
Markdown flavours
The original Markdown from 2004 left many cases undefined, so implementations drifted apart. CommonMark is the effort to specify it precisely, and most modern tools follow it. GitHub Flavored Markdown (GFM) builds on CommonMark and adds tables, task lists (- [ ]), strikethrough and automatic links. If a document renders differently on two sites, the difference is almost always the flavour — tables and nested lists are the usual casualties.
The same content in both
A heading, a bold word and a link in Markdown:
## SetupRun the **install** script, then read the [docs](https://example.com).
And what it becomes in HTML:
<h2>Setup</h2><p>Run the <strong>install</strong> script, then read the <a href="https://example.com">docs</a>.</p>
The Markdown is shorter and readable as plain text; the HTML is what the browser actually needs.
Security: raw HTML in Markdown
Because most Markdown renderers pass inline HTML straight through, rendering Markdown written by other people — comments, issues, profile text — can let them inject scripts. Sites that accept user Markdown either disable raw HTML or sanitise the rendered output against an allowlist of tags and attributes. If you render user input, do the same; and when you need to show HTML as text rather than run it, escape it first with an HTML entity encoder.
Accessibility and structure
Both can produce accessible pages, but Markdown nudges you towards good structure: headings are real headings and lists are real lists. HTML gives you more control — alt text on every image, lang attributes, table captions and header cells — but nothing forces you to use it. Whichever you write in, keep one h1, do not skip heading levels, and describe images properly (our guide to writing alt text covers how).
A practical rule
- Writing prose that someone else will maintain: Markdown.
- Building layout, components, forms or anything interactive: HTML (and CSS).
- Mostly prose with one awkward element: Markdown with a small block of inline HTML.
If you are drafting long Markdown documents, our word counter and reading time calculator work on the raw text.
Frequently Asked Questions
Is Markdown a replacement for HTML?
No — Markdown is converted into HTML. It's a faster way to write common formatting, not a substitute for HTML's full capabilities.
Can I use HTML inside Markdown?
Yes. Most Markdown processors allow raw HTML blocks, so you can mix in HTML when Markdown falls short.
Which should I learn first?
Markdown for writing content quickly; HTML when you need control over structure and styling. They complement each other.