Choose your email workflow
What is the difference between MJML.ai and MJML?
MJML is the open-source markup language and compiler for responsive email. MJML.ai is a web application that adds AI generation and repair around MJML. You can use the framework directly, or use MJML.ai to get to a draft you can review and edit.
What MJML gives you
The MJML project provides components such as sections, columns, text, and buttons. Its compiler turns that source into responsive HTML. The official documentation covers its free online editor, command-line use, Node.js integration, and validation.
If you already know the layout you want and are comfortable writing markup, those tools give you a direct path from source to HTML. A local build also lets you keep compilation alongside the rest of your application code.
Compare the workflows
These are different parts of the email-building process. Choose based on what you have in hand and the work you want help with.
| Your decision | MJML framework and tooling | MJML.ai |
|---|---|---|
| Starting point | MJML framework and toolingMJML source you write or adapt from a template. | MJML.aiA written brief, a template preset, or existing MJML or HTML. |
| Main job | MJML framework and toolingCompile MJML components into responsive email HTML. | MJML.aiGenerate or repair editable MJML, then preview and export the compiled HTML. |
| Where you work | MJML framework and toolingThe free editor linked from mjml.io, a local CLI, or a Node.js integration. | MJML.aiThe MJML.ai browser workspace. |
| Validation | MJML framework and toolingThe compiler reports validation issues; strict and soft validation modes are documented. | MJML.aiThe repair workflow shows before-and-after validation results and a summary of changes. |
| Keeping the source | MJML framework and toolingKeep your MJML files in your own project. | MJML.aiCopy or download MJML and HTML, then keep editing them in your own tools. |
When MJML.ai is useful
Start here when you have an email brief and want a first MJML draft, or when an existing template needs repair. You can inspect the source and compiled preview, review validation results, and copy or download the output. For legacy email HTML, use the HTML-to-MJML workflow to rebuild it as editable MJML.
For a starting layout without a blank canvas, browse the free MJML templates. AI generation and repair are separate from the open-source compiler; review the available credit and sign-in information in the workspace before starting a repair.
Can I use MJML.ai output with my own compiler?
Yes. Download the MJML source and keep it in your project. Compile it with your chosen MJML version and check its validation output. A different compiler version or custom components can change the result, so preview the HTML produced by the version you will actually ship.
Do either of these replace an email sending platform?
The workflow discussed here ends with email code. Import the HTML into your sending platform, verify its merge tags and links, and send a test through that platform. MJML.ai does not send your campaign.
Does valid MJML mean the email is ready to send?
Validation checks markup; inbox testing checks the final message. Review desktop and mobile layouts, links, images, and accessibility. Then use the HTML email size checker and the email QA checklist for the final pass.