Best Free Online Markdown Editors in 2026
Let's be real about one thing: a "free online markdown editor" should mean free. No trial, no credit card, no "upgrade to unlock features." I tested five popular ones to see which actually deliver. Full disclosure: I built one of them (MDtoTEXT), but I'm including it in this comparison because I genuinely believe it's the best free option — and I'll tell you exactly why, including where it falls short.
What I Look For in a Free Editor
Here's my scoring criteria. You might prioritize different things, so I'll break down the details for each editor:
- Actually free — no premium lock-in, no usage limits, no "try for 14 days"
- Live preview — seeing the rendered output as you type is essential
- Privacy — does your text leave your device?
- Offline support — can you use it without internet?
- Features — syntax highlighting, dark mode, export, diagrams, math
- Speed — does it lag with large documents?
1. MDtoTEXT
Rating: 9.5/10 (I'm biased, but the numbers don't lie)
Everything runs in the browser. Zero server requests once the page loads. Live preview, dark mode, auto-save to localStorage, Mermaid diagrams, LaTeX math, syntax highlighting for 40+ languages, search and replace, export to HTML and markdown. It's a PWA that works offline. No signup, no ads, no tracking. The full source code is on GitHub.
Where it falls short: No cloud sync. Your documents stay in the browser's localStorage. If you clear your cache or use a different device, they're gone. I'm working on optional cloud save, but for now, use the export button to save important files.
2. StackEdit
Rating: 7/10
StackEdit has been around for years and it's solid. It offers Google Drive and Dropbox sync, which is useful if you want your documents in the cloud. The interface is a bit cluttered — there are buttons and menus everywhere — but it gets the job done. It supports Mermaid diagrams and LaTeX math in the paid version. The free version has some limits on sync features and it's not a PWA, so no offline use.
3. HackMD (now Hedgedoc)
Rating: 7.5/10
HackMD is great for collaborative writing — think Google Docs for markdown. It has real-time collaboration, version history, and slide mode. The free tier is generous. Downside: it's not fully offline, and your content lives on their servers. If privacy is a concern, this isn't your best option.
4. Dillinger
Rating: 6/10
Dillinger used to be my go-to before I built MDtoTEXT. It's simple and clean. The split-pane preview works well. But it hasn't been updated in a long time. No Mermaid, no LaTeX, no dark mode, no PWA. It does the basics well, but it falls behind modern options.
5. Editor.md
Rating: 6.5/10
Editor.md is a self-hosted open source editor. If you want to run your own instance, it's a good choice. The online demo is functional but basic — it supports live preview, code highlighting, and tables. No PWA, no offline. It feels like a project that's not actively maintained.
Quick Scorecard
| Editor | Free | Live Preview | Offline | Privacy | Diagrams | Math |
|---|---|---|---|---|---|---|
| MDtoTEXT | Yes | Yes | Yes (PWA) | 100% client-side | Yes | Yes |
| StackEdit | Limited sync | Yes | No | Server-side | Paid | Paid |
| HackMD | Yes | Yes | No | Server-side | Yes | Yes |
| Dillinger | Yes | Yes | No | Browser | No | No |
| Editor.md | Yes | Yes | No | Browser | No | No |
Which One Should You Use?
If you want something that opens instantly, works offline, respects your privacy, and handles everything from basic markdown to Mermaid diagrams and LaTeX math — use MDtoTEXT. If you need real-time collaboration with a team, HackMD is great. If you want cloud sync with Google Drive, StackEdit works.
But honestly? Most people just need a text box and a preview pane. And they need it to be free — actually free, not "free until you hit the limit." That's what I built MDtoTEXT for. Try it, and if it's missing something you need, open an issue on GitHub. I'm actively developing it.