HTML email builder you can self-host
A visual drag-and-drop editor built specifically for email.
Assemble a template from 78 ready-made blocks, control every row, cell and atom, then export clean HTML — or the editable JSON. No vendor lock-in.
Blocks in.
Email out.
Pick a block
Drag a preset from the library onto the canvas — menus, headers, content, features, calls to action, e-commerce, transactional blocks and footers.
Edit in place
Text, buttons, images, dividers and menus are edited on the canvas; padding, sizes, alignment, colours and links in the settings panel.
Check the mobile view
Switch the preview to 375 px, stack the columns of a row vertically, or hide the parts that don't belong on a phone.
Export it
Take the email as HTML, or the template as JSON to keep working on it later. Undo and redo the whole way there.
78 presets, eight categories
Visual editing, structural control
Every element in a tree
Add, move, copy, rename and delete anything — the tree and the canvas stay in sync.
Five atoms cover it
Text, button, image, divider and menu — with rich text formatting inside text atoms.
Template-wide design
Background colour or image, padding, font and preheader text are set for the whole email.
Mobile is its own view
Switch the canvas between desktop and phone width, then decide per row what happens on small screens.
Edit without losing context
Write and format text right in the email. The tree and settings stay within reach when you need to shape the structure or fine-tune the details.
One template.
two ways out.
The email leaves as HTML written for email clients, not for web pages. The template leaves as JSON you can import back — replacing what's on the canvas or appended to it, validated and sanitised on the way in.
Run it yourself
Card is a Vue app that runs entirely client-side, so a deployment is a static build behind any web server. Clone the repository, run it on your own domain, and extend the block catalog for your team.
Build on it in the open
Card is the open core of MySigMail Card, released under AGPL-3.0. Fork it, extend the block catalog, share your changes under the same licence.
Embedding in a closed product
A separate commercial licence covers embedding the editor in a proprietary SaaS or internal tool without AGPL obligations.
Do I need an account, and where do my templates live?
No account. The editor opens straight to a canvas and autosaves in your browser's local storage — plus whatever you export. There's no cloud storage or server-side template history.
Can I import an existing HTML email?
Not arbitrary HTML. You can import templates exported from Card as JSON — replacing the canvas or adding to it.
Can I build blocks that aren't in the library?
Yes — rows, cells and the five atoms compose freely, so a custom layout is a matter of nesting rather than code. For reusable presets, extend the catalog in your own fork.
Can I use it in my own product?
Under AGPL-3.0, yes — with the same licence for your changes. For closed-source embedding there's a separate commercial licence.
Does it send email?
No. Card builds and exports templates. Sending, contacts and campaign analytics stay with your email platform.
Open the
editor
No account · Autosaves in your browser
