What a .canvas file actually is
JSON Canvas is an open file format for infinite canvas apps, released by the Obsidian team in 2024 and published under the MIT licence at jsoncanvas.org. A `.canvas` file contains just two arrays: `nodes` and `edges`. Every node has an `id`, a `type`, and an `x`, `y`, `width` and `height` in pixels, so the layout you built is preserved exactly rather than being re-flowed by whatever opens it.
There are four node types. A `text` node stores plain text with Markdown syntax. A `file` node stores a path to a file inside your vault (plus an optional `subpath` pointing at a heading or block). A `link` node stores a URL. A `group` node is a labelled visual container for the nodes sitting inside it. Edges record `fromNode` and `toNode`, optionally which side of each card the line leaves and enters, an arrowhead at either end, a colour, and a label.
Because the format is open and documented, a `.canvas` file is not locked to one app. That is the practical argument for it: the layout of your thinking is portable in a way that a proprietary board file is not.
Why file cards show a path instead of the note
A `file` node contains only the path — for example `Projects/Q3 launch.md`. The note's actual text lives in your vault, not in the `.canvas` file. Since this viewer never receives your vault, it renders file cards as labelled placeholders showing exactly which file the card points at, and nothing more. It will not guess at or generate contents it does not have.
That is also the honest answer to what a canvas file is worth on its own: it is the map, not the territory. The structure, the grouping and the connections travel with the file; the note bodies stay where they live.
Is Obsidian Canvas free?
Yes. Obsidian's documentation describes Canvas as a core plugin, which means it ships with Obsidian and is enabled from the core plugin list rather than bought separately. Obsidian itself is free to use for personal use, so using Canvas for your own notes costs nothing. Obsidian's commercial licence applies to using the app for work in a company setting, and paid Sync and Publish are separate add-on services — none of which are required to make canvases.
The format is free in a second sense too. JSON Canvas is MIT-licensed and openly specified, so any application may read or write `.canvas` files without permission or fee.
The card-versus-note trap in Obsidian Canvas
Worth knowing before you commit real thinking to a canvas: Obsidian's documentation states that text-only cards do not appear in Backlinks, and that to make them appear you have to convert them to a file — right-click the card, choose "Convert to file…", name the note and save.
That matters because the whole promise of a linked note system is that ideas find each other later. A card you typed straight onto a canvas is, until you convert it, invisible to the graph and to backlinks — it exists only on that board. If you use Canvas as a thinking surface, it is worth converting the cards that turn out to matter, or drafting them as notes and dragging the notes onto the canvas instead.
Looking for an Obsidian Canvas alternative
The common reasons people go looking are the ones above plus device reach: canvases live inside a vault on the machines you have synced, and sharing one with somebody who does not use Obsidian means exporting an image.
This viewer is a bridge rather than a replacement — it opens the file so you can read it anywhere, and then hands it off to OmniCanvas if you want to keep working on it. Your cards become a note on an infinite canvas that syncs across devices and opens in a browser, with the groups preserved as columns and the connections listed. If you are still shopping around, our [canvas app finder](/tools/canvas-app-finder) compares the options without assuming you have picked one.