Mosaico
A template-based visual email editor with a browser demo and GPL-licensed code for self-hosted integration.
About Mosaico
Mosaico is a visual email template editor. Users choose a template, pick from the template's blocks, and personalize the content, block variants, image placements, sizes, visibility, and URLs. Depending on the template, colors, fonts, text size, and buttons can also be adjusted. The homepage says the templates are responsive and have been tested with major email clients and devices.
For developers, Mosaico supports custom templates through a simple template language. Its code is distributed under the GPL license and is available on GitHub. Image handling has a limit: since April 11, 2025, hotlinking images from mosaico.io is no longer allowed, so users must download and host their own images. The feedback address is for suggestions only, not support requests.
Key features
- Responsive templates with blocks provided by each template
- Drag-and-drop image upload with automatic resizing to fit space
- Global undo and redo system
- Customization of block variants, image placements, sizes, and URLs
- Custom templates built with a simple template language
- Source code distributed under the GPL license on GitHub
Best for: People who want to build responsive HTML email templates visually without hand-coding, and developers who want to self-host or adapt GPL-licensed email editor code.
Good for
- Distributed under the GPL license, with the complete code base on GitHub
- Templates are described as tested across major email clients and devices
- Listed as free on the homepage
Watch out for
- Hotlinking images from mosaico.io is not allowed, so images must be hosted by the user
- Color, font, text size, and button customization depends on the selected template
- The feedback address does not accept support requests
Mosaico at a glance
- Website
- mosaico.io
- Category
- Productivity › Email Tools
- Type
- Online tool
- Pricing
- Free
- Open source
- Yes
- Last checked
- Oct 9, 2026 · Online when checked
- Listed
- Oct 9, 2026
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Mosaico FAQ
Can I link to images hosted on mosaico.io in my emails?
No. As of April 11, 2025, hotlinking images from mosaico.io is no longer allowed because it was abused for phishing. The homepage asks users to download and host their own images.
Where do I get support?
The homepage says the feedback address is for suggestions and feedback only, not support requests. It links to a separate support page for help.
Can I get the source code?
Yes. Mosaico is distributed under the GPL license, and the complete code base is available on GitHub.
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