Mosaico

What Mosaico is

Mosaico is a free, open-source builder for responsive email templates, available on the web or as self-hosted software. Its editor lets users customize an overall theme and the styles of individual elements. Drag-and-drop image uploads are resized to fit available space, and global undo and redo controls support revisions. Custom HTML designs can be adapted for editing through Mosaico’s template language, which determines what content and styles editors can change. Templates can be exported as HTML, and the project says its responsive templates work with major email clients and devices. Mosaico is distributed under the GPL license, with its codebase linked on GitHub. Documentation covers local builds and deployment through web servers such as Apache PHP or Django. Mailtrain supports email editing through Mosaico, and CiviCRM is among the open-source projects using it. Images hosted on mosaico.io cannot be hotlinked; users need to download and host them elsewhere.