An online markdown editor is a browser-based tool that lets you write markdown with a live preview and export to HTML, PDF, or styled .md without installing anything. Six are worth opening a tab for in 2026. Below: a hands-on comparison, an embedded editor you can try right now, and the honest verdict on which one fits which job.
TL;DR — the verdict in 30 seconds
Six contenders, three useful shapes. The short answer:
- Best overall — and yes, mine: mdclaudy — clean editor, AI in the margins, fifteen designed PDF templates at the end.
- Best for zero-friction drafts: Dillinger — no sign-in, instant preview, the original web markdown editor.
- Best for technical docs with math: StackEdit — KaTeX, Mermaid, every extension turned on.
- Best for team collaboration: HackMD — real-time multi-cursor, the only one in this list.
- Best for the fastest preview tab: MarkdownLivePreview — minimal, loads in under a second.
- Best as an embeddable library: Editor.md — drop into your own product, MIT licensed.
| # | Editor | Best for | Price | Platforms | Export | AI | Source |
|---|---|---|---|---|---|---|---|
| 1 | mdclaudy· us | Writers who want a designed PDF at the end of an online draft | Free 50 docs · Pro $8/mo | Web (all OS) | ★★★★★ | Yes | Closed |
| 2 | Dillinger | Quick one-off drafts you want to write and export immediately | Free | Web | ★★★★★ | — | Open |
| 3 | StackEdit | Power users who want every markdown extension turned on at once | Free · Premium $5/mo (limited) | Web | ★★★★★ | — | Open |
| 4 | HackMD | Teams that want real-time collaborative markdown like Google Docs | Free · Prime $5/mo | Web | ★★★★★ | Yes | Open |
| 5 | MarkdownLivePreview | The fastest possible 'just show me the preview' tab | Free | Web | ★★★★★ | — | Open |
| 6 | Editor.md | Self-hosted internal tools that need an embedded markdown editor | Free (open source) | Web (self-host) | ★★★★★ | — | Open |
Want to try mdclaudy without leaving this page? Open the editor in a new tab. No sign-up required for the first draft. For the wider landscape that includes desktop apps, see the nine-editor comparison.
Five things to know about online markdown editors
The category is older than it looks — Dillinger launched in 2014, StackEdit in 2013 — and the shape has settled. Before you pick a tool, here’s what actually matters.
- Autosave is not universal. Dillinger and MarkdownLivePreview save to browser localStorage — clear your cookies, lose your draft. mdclaudy and HackMD save to their own servers. StackEdit syncs to whichever cloud you connect. If your draft matters, know where it lives.
- Export quality varies wildly.Most online editors export PDF by handing your HTML to the browser’s print dialog. The result looks like a printed web page. Only mdclaudy ships templates designed for the page itself.
- Sharing is the killer feature of HackMD.No other tool in this list lets two people edit the same markdown doc at the same time with cursors. If you write specs, post-mortems, or design docs with anyone else, that’s decisive.
- AI is still a sidebar in most of them. HackMD bolted it on. The others ignored it. mdclaudy was built around it — AI in the margins of the document, opt-in per action, your choice of model. See the AI markdown editor comparison for the dedicated angle.
- Themes matter less than you’d think. Most online editors ship a handful of themes and you pick once. The editor you stare at for hours has to be calm; dark mode is table-stakes; anything else is decoration.
The six editors, ranked
Each card is a verdict, the price as of May 2026, strengths and weaknesses I noticed across writing the same 2,000-word draft in each of them, and a single sentence on the shape of writer it suits. The editors that didn’t survive an honest test (a handful of dead EMD sites and abandoned hobby projects) aren’t ranked here.
mdclaudy
Conflict of interest declared up top: this is my tool. mdclaudy is the online markdown editor I wanted to use myself — a clean Tiptap-based surface with slash commands, optional AI in the margins (Ask, Generate, Rewrite, Continue), a real library (folders, collections, tags, ⌘K), and the differentiator that makes the rest of this comparison tilt: fifteen typeset PDF templates and DOCX export. Where it gives ground to Dillinger and StackEdit: it's not anonymous — you sign in. Where it doesn't: a Dillinger draft is a tab you'll lose; an mdclaudy draft is a library you can come back to in a year.
- +Fifteen designed PDF templates plus DOCX — no second tool needed
- +AI in the margins, choose your model (Claude, GPT, Gemini, 200+)
- +Library: folders, collections, tags, ⌘K palette, drag-drop import
- +Markdown stays the source of truth — export back to .md any time
- −Requires sign-in — not the 'open a tab and type' flow
- −Younger product than Dillinger or StackEdit
- −No native desktop or mobile app yet
- −No real-time collaboration
Dillinger
Dillinger has held the top of the SERP for 'online markdown editor' for almost a decade for one reason: it works the moment you land on it. No sign-in, no onboarding, no library — open a tab, type, export. The split-pane live preview is responsive, the export menu covers HTML, PDF and styled .md, and the cloud-sync integrations with Dropbox / Google Drive / OneDrive solve persistence without an account. What it doesn't do: AI, designed templates, project organisation, version history. For a quick one-off it remains the cleanest answer on the web.
- +Zero friction — no sign-in, just type and export
- +Open source under the MIT license
- +Cloud-sync to Dropbox, Google Drive, OneDrive, GitHub
- +Reliable export to HTML, PDF, styled markdown
- −No library — every draft is its own browser tab to remember
- −No AI assistance
- −PDF export is plain — no designed templates
- −No version history without external sync
StackEdit
StackEdit is the other decade-old incumbent and the one with the deeper feature set. KaTeX for math. Mermaid diagrams. UML. Footnotes. Abbreviations. Critic Markup. Custom CSS. It does everything CommonMark-plus that you can think of, syncs to GitHub / Google Drive / Dropbox, and even runs offline as a PWA. The UI is dense — the chrome takes up more screen than the writing surface — and the export, while flexible, looks generic. For technical writers who want every extension in one place, StackEdit is unbeaten. For prose, it's overengineered.
- +Most complete markdown extension support of any web editor
- +KaTeX math, Mermaid, UML, footnotes, abbreviations, Critic Markup
- +Syncs with GitHub, Google Drive, Dropbox, CouchDB
- +Works offline as a PWA
- −UI is dense — chrome takes up more space than the editor
- −No AI, no designed templates
- −Premium tier is fiddly to justify
- −Generic-looking export
HackMD
HackMD (and its open-source sibling CodiMD) is the only entry on this list with real-time collaborative cursors — Google Docs for markdown, basically. It's used by engineering teams for shared specs, post-mortems, and design docs that need more than one writer in the doc at once. It does meetings notes, slide-mode presentations from markdown, and book-mode for multi-page docs. Where it weakens: the export is plain, the AI features (added in 2024) are bolted on as a sidebar rather than integrated into the typing surface, and the free tier has hard limits on private notes. For solo writers, look elsewhere; for engineering teams, this is the answer.
- +Real-time multi-cursor collaboration — unique in this list
- +Slide mode and book mode built in
- +Open source (CodiMD) for self-hosting
- +Strong GitHub integration
- −AI bolted on as a sidebar, not integrated
- −Free tier limits private notes hard
- −Export is plain — no designed templates
- −UI is engineer-oriented, not writer-oriented
MarkdownLivePreview
MarkdownLivePreview is the minimal answer — a single page with two panes, no chrome, no settings, no account. It exists because Dillinger and StackEdit grew over the years and people wanted the original 2012-era promise back: open tab, type markdown on the left, see rendered HTML on the right. That's the entire product. It does it well, loads in under a second, and supports basic export. It has no library, no sync, no AI, and the PDF export defers to the browser print dialog. For a thirty-second preview check, it's perfect. For anything else, you'll outgrow it in an afternoon.
- +Loads in under a second — fastest live preview on the web
- +Zero chrome, zero settings, zero account
- +Open source
- +Mobile-friendly out of the box
- −No library, no sync, no autosave guarantee
- −PDF export is browser-print-dialog only
- −No AI, no templates, no themes
- −Outgrown the moment you have a second draft
Editor.md
Editor.md is less a product than a JavaScript library — an embeddable open-source markdown editor with live preview, syntax highlighting, KaTeX, Flowchart and Sequence diagrams. It's mostly used by Chinese developers and built into internal CMSes and forum software. As a standalone editor for a writer to actually draft in, it's dated and the English documentation is sparse. As a library to drop into your own product when you need a markdown editor component, it's solid. Different shape, different audience.
- +Embeddable as a JavaScript library, MIT licensed
- +Live preview, KaTeX, Flowchart, Sequence diagram support
- +Self-hostable, no external dependencies
- +Long history of production use in CMS and forum software
- −Standalone UI is dated
- −English documentation is sparse
- −No AI, no library, no designed templates
- −Maintenance has slowed
When to use an online editor (and when not to)
Online markdown editors are a real category but they aren’t always the right answer. The honest decision framework:
Use an online editor when
- You switch machines often and don’t want install friction on every one.
- You need to write quickly on a borrowed machine, a Chromebook, or your work laptop where you can’t install software.
- You’re collaborating with someone else in real time (HackMD specifically).
- You want to keep the draft in the same place as your other web tools — a library accessible from any browser.
- The export is the point and the online tool has the design you need (mdclaudy specifically, for designed PDFs).
Use a desktop editor when
- You need guaranteed offline — flights, trains, anywhere flaky.
- You want the absolute lowest typing latency. Native apps still win on this.
- You want a deep plugin ecosystem (Obsidian is the obvious example).
- You’re working with truly sensitive material that shouldn’t leave your machine.
- You write long-form prose and want the typography and focus tools of a tuned desktop writing app — see the writer-specific roundup.
An online markdown editor is a tab. Decide whether you’re opening a draft or a library.
Privacy: where your draft actually lives
The privacy story for online markdown editors is genuinely varied and worth understanding before you paste anything sensitive.
- Dillinger and MarkdownLivePreview are local-first in the browser. Your draft sits in localStorage on your machine and nothing leaves unless you opt in to a cloud sync. Open source, MIT-licensed — you can read the code.
- StackEdit defaults to localStorage but most users enable Google Drive or Dropbox sync — at which point the confidentiality matches whatever you trust those services with.
- HackMD stores your notes on their servers. The free tier defaults notes to public unless you upgrade — read the tier carefully.
- mdclaudy stores your library on its servers behind your account. The .md file underneath is the source of truth and you can export it back any time. No training on your documents, no resale of content.
- Editor.md is a library you self-host, so the privacy question is whatever the surrounding product chooses.
For genuinely sensitive material — unreleased financials, legal drafts, medical writing — default to a local-first desktop editor. Online tools are convenient but they aren’t the right shape for that work.
Try mdclaudy in your browser
I’ve written this post entirely in mdclaudy and exported it through the Editorial template for the print copy I’m keeping on my desk. If you want to feel the typing surface, you don’t need to read another paragraph: open the editorin a new tab and write a few sentences. The first draft saves locally before you sign in. If you like it, sign up and the draft moves into your library; if you don’t, close the tab and you’ve lost nothing.
The differentiator that won’t come through in 90 seconds of typing is the export step. When you’re ready to ship the draft, pick a template — Editorial for essays, Whitepaper for reports, Manuscript for prose, Sales Proposal for client work — and the PDF that comes out looks like it was designed. The full template gallery is here.
Frequently asked questions
Related reading
- The 9 Best Markdown Editors of 2026 — the wider field including desktop apps.
- The Best AI Markdown Editor in 2026 — for the AI-specific angle.
- The Best Markdown Editor for Writers — novelists, journalists, bloggers, essayists.
- Markdown to PDF — the export step every online editor leads to.
- Markdown to HTML — the other major export path online editors handle.
How I tested
Each editor was used to write the same 2,000-word draft from scratch, on a 2024 MacBook Air (M3, 16GB), in Chrome and Safari. Typing latency was measured by feel and timed across the draft. Export was tested to PDF and HTML where supported, and the result was opened in Acrobat and compared. Pricing was current as of May 2026. Editor versions: Dillinger 1.18.x, StackEdit 5.x, HackMD 2.x, MarkdownLivePreview current, Editor.md 1.5.0, mdclaudy current build.
Conflict of interest: mdclaudy is my product. The ranking position reflects the headline question — best online markdown editor for most users — not the narrower question (best online markdown editor for shipping a designed PDF) which would put mdclaudy first regardless. If the conflict bothers you, the runner-up at the top of the list is Dillinger and the post above doesn’t hide anything Dillinger does better than mdclaudy.
The honest final word
Most online markdown editors are tabs. You open one, type a draft, export, close. That’s a real use case and Dillinger nails it. A few are libraries — places to keep drafts you’ll come back to. That’s a different shape and mdclaudy was built for it. Pick the one that matches the moment you’re in.
If you’re writing something that has to look designed at the end, that’s the gap mdclaudy was built for. The CTA below is the only pitch in this whole post — read it or don’t, no hard feelings.