About MJML
Overview
MJML is an open-source markup language and engine that simplifies crafting responsive HTML emails. It abstracts the complexity of email HTML so developers can write semantic, component-based code that compiles into bulletproof, responsive email templates.
The framework handles cross-client quirks automatically — including Outlook — and keeps email designs up to date as email clients evolve. Created by the Mailjet developer team in 2015, MJML was born from the need to make responsive email design fast, reliable, and maintainable.
Key Benefits
- Semantic syntax reduces the amount of code needed to build email templates.
- Responsive by default on most email clients, including Outlook.
- Reusable and extensible components let developers focus on content instead of styling.
- Automatically updates compiled email HTML when email client specs change, staying current without manual rework.
- Open-source framework backed by the Mailjet team and community contributions.
How It Works
A developer writes email layouts using MJML tags such as <mj-section>, <mj-column>, <mj-image>, and <mj-article>. The MJML engine transpiles that markup into responsive HTML email with nested tables and inline CSS, ready to send through any email service provider.
Use Cases
- Email developers who want to stop hand-coding complex HTML table layouts for each campaign.
- Design teams building drag-and-drop email editors — MJML powers the Mailjet Passport interface and a Figma plugin.
- Marketing teams that need consistent, responsive email templates across multiple email clients and devices.
- Open-source contributors who extend MJML by building custom components for specialized layouts.
- Agencies and in-house teams producing high-volume transactional or newsletter emails that must render reliably on mobile, desktop, and Outlook.
Why Choose This Product
MJML is suited for developers and teams who produce responsive email regularly and want to reduce coding time while staying compatible with modern email clients. The framework is open source and free to use, with no paid tier or pricing publicly listed on its site.
