> ## Documentation Index
> Fetch the complete documentation index at: https://docs.allgoodhq.com/llms.txt
> Use this file to discover all available pages before exploring further.

# What MJML is

> MJML is the format allGood email components are written in. You can build and edit components without ever typing it.

**MJML** is a markup language built for email. Every [email component](https://docs.allgoodhq.com/mk/content/email/components/index.md) in allGood is stored as a small MJML file.

## Why email needs it

Email programs such as Outlook draw messages in their own, often odd, ways. An email that looks right in one program can break in another. Making one layout hold up everywhere takes a lot of fiddly code.

MJML lets you describe the layout in a few simple tags, such as a section, a column, and a button. allGood then turns those tags into email-safe HTML before any email is sent. You see the finished result in the preview.

## Do you need to know it?

Most people do not. You can ask Mary, allGood's AI, to build or change a component, and edit the result in plain language. See [Editing an email component](https://docs.allgoodhq.com/mk/content/email/components/editing-an-email-component.md).

MJML matters only if you want to write or adjust component code yourself. If that is you, the developer articles cover it:

* [How MJML works](https://docs.allgoodhq.com/mk/developer/email/how-mjml-works.md)
* [Write an email component](https://docs.allgoodhq.com/mk/developer/email/how-to-write-email-components.md)

If you build templates in Marketo, HubSpot, or plain HTML today, [Compare MJML with other email tools](https://docs.allgoodhq.com/mk/developer/email/compare-mjml-with-other-tools.md) shows how each one maps to MJML.

## Related articles

* [Email components](https://docs.allgoodhq.com/mk/content/email/components/index.md)
* [Editing an email component](https://docs.allgoodhq.com/mk/content/email/components/editing-an-email-component.md)
* [Setting up and reviewing email components](https://docs.allgoodhq.com/mk/content/email/components/setting-up-and-reviewing-email-components.md)


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