Free Markdown editor
Write once.
Render the same everywhere.
mdstudio is a free, open-source Markdown editor with a live preview that matches GitHub, dev.to and Obsidian, and a checker that flags anything that won’t travel. Then export a clean file that just works.
No account needed. Drafts stay in your browser.
From draft to published, without surprises
- 1
Write
Draft in a full editor with a complete formatting toolbar, tables, footnotes, math and diagrams.
- 2
Check
Pick where it will be published. mdstudio previews it the way that platform renders it and flags what won't travel.
- 3
Export
Copy or download clean Markdown, or a self-contained HTML file. No lock-in, no account.
See what won’t travel
This is the real checker running in your browser. Edit the Markdown, switch the target, and watch the report change. The same sample is clean on one platform and broken on another.
Loading the checker…
Everything a Markdown writer needs
What you see is what ships
Strict CommonMark + GFM rendering. No preview-only line breaks or smart quotes.
Portability checks
Flags raw HTML, local images, wiki-links and anything else that won't render the same everywhere.
Math and diagrams
KaTeX and Mermaid built in, with a warning wherever your target platform can't render them.
Import, paste, drop
Open .md files, or paste from Google Docs, Notion and the web. It's converted to clean Markdown.
Clean export
Download or copy .md with UTF-8 and LF endings, optional normalizing, and self-contained images.
Private by default
Drafts live in your browser. No account, no uploads, and AI keys never leave your session.
Pick where you publish
Each target profile changes the preview, the checks and the toolbar warnings, so you find out before your readers do.
GitHub (GFM)
Tables, task lists, footnotes
Strict CommonMark
Works everywhere
dev.to / Hashnode
GFM, no raw HTML
Obsidian
GFM + highlights, wiki-links
Guides to portable Markdown
What differs between GitHub, dev.to, Obsidian and CommonMark, and how to write Markdown that survives all of them.
Portable Markdown: Why It Renders Differently Everywhere
Why the same Markdown looks different on GitHub, dev.to and Obsidian, and a checklist for making your writing render the same on every platform.
CommonMark vs GitHub Flavored Markdown: What Differs
A clear comparison of CommonMark and GitHub Flavored Markdown: tables, task lists, strikethrough, footnotes, autolinks and alerts, and when each one matters.
Obsidian to GitHub Markdown: Wiki-links, Callouts & More
How to share Obsidian notes outside Obsidian: convert wiki-links, highlights, callouts and embeds so they render on GitHub, dev.to and static sites.
About mdstudio
mdstudio is a free, open-source, local-first Markdown editor and portability checker. Write in a full-featured editor with a complete formatting toolbar, watch a live preview that matches what GitHub, dev.to, Obsidian or a strict CommonMark engine will render, and get clickable warnings for anything that will not travel: raw HTML, local images, wiki-links, math, Mermaid diagrams and trailing-space line breaks. Drafts autosave in your browser with no account, import from .md files or pasted Google Docs and Notion content, and export clean UTF-8 Markdown or self-contained HTML. Optional AI writing helpers use your own API key. mdstudio is MIT licensed, runs free in the browser and can be self-hosted with Docker.
Who it’s for
- Technical bloggers publishing to dev.to, Hashnode and static site generators
- Developers writing READMEs and documentation for GitHub
- Obsidian users who share notes outside Obsidian
- Documentation teams who need Markdown that renders the same in every tool
Frequently asked questions
+What is mdstudio?
mdstudio is a free, open-source Markdown editor with a live preview and a portability checker. You write Markdown, see how it will render on GitHub, dev.to, Obsidian or a strict CommonMark engine, and fix anything that would look different before you publish.
+How is mdstudio different from other Markdown editors?
Most editors render Markdown their own way, so a post can look right in the editor and wrong where you publish it. mdstudio keeps the raw Markdown as the single source of truth, renders it without preview-only tricks, and flags syntax that other platforms handle differently, such as raw HTML, local image paths, wiki-links, math and Mermaid.
+Is mdstudio free and open source?
Yes. mdstudio is free to use in the browser and released under the MIT license. The source code is on GitHub, and you can self-host it with Docker.
+Are my documents private?
Yes. Drafts are saved in your browser's IndexedDB and are not uploaded anywhere. There is no account to create. If you use the optional AI helpers, your API key stays in memory for the session and requests go directly from your browser to the provider you choose.
+Which Markdown flavors and platforms does it check?
Choose a target profile: Strict CommonMark, GitHub Flavored Markdown, dev.to or Obsidian. The preview and the portability checks adapt to the profile, and the toolbar warns before you insert syntax the target does not support.
+Does mdstudio support math, diagrams, tables and footnotes?
Yes. It renders KaTeX math, Mermaid diagrams, GitHub-style tables, task lists, footnotes and alert blocks, and shows when a target platform may not render them.
+How do I export my writing?
Download or copy clean Markdown with UTF-8 and LF line endings and optional whitespace normalizing, or export a standalone HTML file with images and math included.
+Can I self-host mdstudio?
Yes. A Docker image runs the whole app in a single container with a persistent volume. See the project on GitHub for the compose file and instructions.
Write something that renders the same everywhere
Free, open source and private. Open the editor and start typing.