Mosaico review
A free, developer-oriented editor for building responsive HTML email templates.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Mosaico is an open-source JavaScript library and web-based editor for creating responsive HTML emails. It is aimed at developers who want to embed an email builder in their own applications, customize reusable layouts, or run the editor themselves. The drag-and-drop interface works with content blocks, editable text and images, block cloning, movement and removal, and style controls for colors, fonts, sizes and buttons. A hosted website provides a live demo, while self-hosting instructions and source code under the GPL license support developer-led deployment.
The editor’s strongest area is template construction. Mosaico supports template-driven customization and lets developers create custom templates with its template language. Image uploads include automatic resizing, and global undo and redo help manage changes during editing. Responsive email template editing, test-email sending and reusable blocks make the product suitable for teams that need a focused authoring layer rather than a broader campaign system. Its free, open-source model also avoids a conventional paid-plan comparison: the published product description presents Mosaico as a library with a hosted demo and self-hosting path.
Mosaico is a narrower choice than a full email marketing platform. The documented feature set focuses on editing and template development, without integrations, advanced workflow features or verified HTML export. There are also no AI features. Choose it when developer control, source availability and custom deployment matter more than an integrated ecosystem. Teams seeking connected campaign workflows, broader platform integrations or a confirmed export workflow should choose another email design tool.
Mosaico pros and cons
- Where it wins
- Free and open source with web and self-hosted options
- Responsive drag-and-drop editing with reusable templates
- Custom templates, image resizing, undo/redo and test emails
- Where it doesn't
- No documented integrations with other platforms
- Advanced workflow features are not included
- Verified HTML export is not available
Mosaico fact sheet, pricing and score →
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