A canvas for Markdown notes on the Mac, in Obsidian's format

Checked November 2026 against jsoncanvas.org and Obsidian's Canvas help. Coffee isn't affiliated with Obsidian.

Some thinking doesn't fit in a list. A plan with five parts and arrows between them, the scenes of a story, the people in a project and who talks to whom: you want to put things down where you can see them, and move them about.

That's what a canvas is for. Coffee can make one, and open the ones you already have, because it uses the same file format as Obsidian.

The format: JSON Canvas

JSON Canvas is an open file format for boards like this. It was made for Obsidian, it's open source under the MIT licence, and its files end in .canvas. Inside, a canvas is a short JSON file: a list of cards, each with a position and a size, and a list of arrows between them.

Because it's open, a board isn't locked in one app. Obsidian saves its canvases this way, so a .canvas file from an Obsidian vault opens in Coffee, and one made in Coffee opens in Obsidian. For what else carries over from a vault, see Obsidian alternatives for Mac.

Coffee writes the file the way Obsidian does, one card per line, and keeps anything it doesn't use as it was. A card or arrow Coffee can't read is kept and written back too, so opening a board in Coffee never loses what another app put there. A file Coffee can't read at all is shown empty and never written over.

Making a canvas

Choose File > New Canvas…, give it a name, and Coffee makes an empty .canvas file in your notes folder and opens it in a window of its own. File > Open Canvas… opens one from anywhere, and in Finder you can use Open With > Coffee.

A board holds four kinds of card, which you add from the toolbar:

• Text. Markdown, written on the card itself. Headings show larger, and bold, italics and links show as written. Double-click empty space to start one, double-click a card to write in it again, and press Esc when you're done.
• Note. A note from your library, showing its title and opening lines. Double-click it and the note opens in Coffee. A private note shows only that it's private.
• Link. A web address. The card shows the site and the address, and a double-click opens it in your browser.
• Group. A labelled area to gather cards in. Moving a group carries the cards inside it.

Choose a card and pick one of six colours from the toolbar, or none. The colours are the format's six preset ones, so Obsidian shows them the same.

Arrows

Choose a card and a dot appears on its edge. Drag the dot onto another card and Coffee draws an arrow between them, curved, from the sides that face each other.

Click an arrow to choose it, and Shift-click to choose more. Double-click an arrow to give it a label. Delete removes the chosen arrows and leaves the cards.

Moving around

• Drag a card to move it, and its corner to resize it.
• Drag across empty space to draw a box. The cards wholly inside it are chosen, and Shift adds to what's chosen.
• Scroll to move around the board, or hold Space and drag. Command-scroll or pinch to zoom. Fit, in the corner, brings everything into view.
• The arrow keys nudge what's chosen by 2 points, or 20 with Shift.
• ⌘A chooses every card, ⌘D duplicates what's chosen with the arrows between those cards, Delete removes it, and ⌘Z undoes. A whole drag is one step to undo.

Saving, and other apps

There's nothing to save. A change is written a moment after you make it, and again when the window closes or Coffee quits.

If the file changes somewhere else while the board is open, say in Obsidian or on another Mac, Coffee notices. With nothing unsaved, it shows the new version when the window comes back to the front. If you'd changed something too, the other version stays where it is, and yours is kept beside it as a second file with "(Coffee)" in its name. Coffee says so on the board, so you can compare the two.

How this compares

Obsidian's Canvas does a good deal more, and if you live on a canvas it's the better tool. Its help lists cards for images, audio and PDFs, web pages shown inside the card, note cards narrowed to one heading or block, base cards, and a whole folder dropped on at once. A group can have a background picture, and a canvas can be embedded in a note.

Coffee shows text, notes, links and groups. A picture or PDF on an Obsidian board isn't drawn in Coffee, though it's kept in the file, and a link shows its address rather than the page. A note card shows the whole note's start, not one heading.

What Coffee adds is a canvas next to an editor that's built for the Mac, with the same files you'd use in Obsidian. If you want to see how notes link rather than arrange them by hand, the graph of your notes draws that for you, and Coffee vs Obsidian covers the rest of the choice.

Questions

Can Coffee open Obsidian canvas files?

Yes. Obsidian saves canvases as .canvas files in the open JSON Canvas format, and Coffee reads and writes the same format. Text, note, link and group cards are shown. Others are kept in the file but not drawn.

Where does Coffee keep a canvas?

As a .canvas file. File > New Canvas puts it in your notes folder, and you can open one from anywhere with File > Open Canvas.

Can a canvas card open a note?

Yes. Add a note card from the toolbar, and double-click it to open the note in Coffee.

Can I label an arrow on a canvas?

Yes. Double-click the arrow and type a label, or leave it empty for none.

What happens if another app changes the canvas while it's open?

If you have nothing unsaved, Coffee shows the new version. If you'd changed something too, the other version stays and yours is saved beside it with "(Coffee)" in the name.

Coffee runs on a Mac with macOS 15 or later, and on iPhone and iPad, which open the same .canvas files. It's free for 14 days without a card, then €3 a month, €29 a year, or €79 once with two years of updates, and one purchase covers all three.