mosaico.io

What it is

Mosaico.io is a free responsive email template editor designed to help users create email templates that work across different devices and major email clients, without needing a specialist team or extensive compatibility testing. The project is provided by the Italian email marketing company VOXmail.it. The page clearly states that the full codebase is available on GitHub and released under the GPL license.

Core capabilities

In terms of functionality, Mosaico focuses on email template design rather than general-purpose website building. It offers template selection, template block editing, content personalization, block variants, image positioning and resizing, URL and visibility controls, and more. The editing experience supports drag-and-drop image uploads, automatic image scaling to fit available space, and global undo/redo, reducing the friction of frequent saving, confirmation, and rollback. Styling options vary by template, but may include colors, fonts, text sizes, buttons, and other elements. For developers, it supports custom templates and a simple template language; the official copy says an HTML design can be adapted for Mosaico within a few hours.

Open source, pricing, and integrations

One of Mosaico’s key strengths is that it is open source under the GPL license, making it suitable for teams that want control over the source code, need secondary development, or plan to embed an email editor into internal systems. On pricing, the page only shows “Free email template builder” and does not disclose commercial plans, enterprise support, or hosted service fees. API/SDK availability, a plugin marketplace, and integrations with email service providers are also not clearly specified. As a result, if you plan to connect it to an existing email marketing platform, you will still need to evaluate the source code, documentation, and actual development cost.

Pros, cons, and who it is for

Its advantages are a clear product focus, a low barrier to entry, a friendly drag-and-drop editing experience, and an emphasis on template usability across major email clients and devices. Being open source also improves controllability. Its limitations are that the page does not show detailed documentation, technical support SLA, team collaboration, permissions, version management, or other enterprise-grade capabilities. Also note that starting from April 11, 2025, mosaico.io no longer allows image hotlinking, so users must download and host images themselves.

Access from China and alternatives

The page does not provide information on access from mainland China. Real-world availability needs to be tested for network connectivity, GitHub access, and image asset loading. There is also no information about payment methods. If you need more complete commercial services or ecosystem integrations, alternatives to compare include MJML, Stripo, BeeFree, Unlayer, and Mailchimp Email Builder.