MJML to Responsive Email HTML Converter
Compile MJML markup into production-ready, responsive HTML email. Paste an MJML document and get clean HTML with Outlook (MSO) conditionals, inline styles and media queries — choose beautified, minified or raw output and a validation level. Runs entirely in your browser.
Input
Beautified is easier to read; minified is smaller to send; raw is the compiler's exact output.
Soft lists issues but still compiles. Strict reports them and produces no HTML. Skip disables validation.
Keeps author-written HTML comments. Outlook (MSO) conditional comments are always kept.
Output
Compiled email preview will appear here.
Validation Messages
| Level | Line | Element | Message |
|---|---|---|---|
| No data yet | |||
Guides
Turn concise MJML markup into production-ready, responsive HTML email — the kind that renders correctly in Gmail, Apple Mail, Outlook and dozens of other clients. Paste your MJML on the left and get clean, send-ready HTML on the right, along with a live preview and any validation messages.
What is MJML?
MJML (Mailjet Markup Language) is an open-source markup language designed specifically for building responsive email. Coding HTML email by hand is famously painful: email clients are stuck decades behind browsers, so you have to nest tables, sprinkle in Microsoft Outlook "MSO" conditional comments, inline every style, and test across a maze of clients. MJML hides all of that behind a small set of semantic tags — <mj-section>, <mj-column>, <mj-text>, <mj-button>, <mj-image> — and compiles them down to the bulletproof, table-based HTML those clients actually need.
A minimal document looks like this:
<mjml>
<mj-body>
<mj-section>
<mj-column>
<mj-text>Hello world</mj-text>
</mj-column>
</mj-section>
</mj-body>
</mjml>
The compiler expands that into a full HTML document with a responsive grid, inlined styles, media queries and Outlook fallbacks.
Why use it?
- Responsive by default. Columns stack automatically on mobile — no media-query wrangling required.
- Cross-client reliability. The generated HTML includes the MSO conditional comments and table scaffolding that keep Outlook (still a huge share of corporate inboxes) from mangling your layout.
- Faster iteration. A dozen lines of MJML replace hundreds of lines of nested tables, so newsletters and transactional emails are far quicker to build and maintain.
- Portable output. The result is plain HTML you can paste into any email service provider (Mailchimp, SendGrid, Postmark, Amazon SES, your own SMTP) or transactional template.
How to use this converter
- Paste or type your MJML into the MJML Source box (or click "Try an example" for a starter template).
- Pick an Output Style: Beautified (indented and easy to read), Minified (whitespace stripped for smaller payloads), or Raw (the compiler's exact output).
- Choose a Validation level: Soft lists issues but still compiles, Strict stops and reports problems instead of producing HTML, and Skip turns validation off.
- Optionally toggle Keep HTML comments. Outlook conditional comments are always preserved regardless of this setting.
- Copy or download the Responsive Email HTML, and check the Validation Messages table for any warnings or errors.
Why doesn't the preview look exactly like the final email?
The on-page preview is a best-effort structural view. For safety, it is rendered through an HTML sanitizer that strips <style> blocks, images, links and certain layout attributes — so the responsive CSS and imagery won't appear there. The copyable HTML output is the complete, unmodified compiler result; send that (or open the downloaded .html file in a browser or an email-testing tool) to see the real rendering.
Is my content private?
Yes. Compilation runs entirely in your browser — your MJML is never uploaded to a server.