An infinite canvas is a workspace with no fixed page size or edge — you pan and zoom across it rather than turning a page — so images, notes and groups can be arranged at whatever scale the idea actually needs instead of being squeezed into a slide or cropped at a boundary.
The term comes out of whiteboarding software, but the idea underneath it predates any app: a corkboard is already infinite in the sense that matters, because you can keep pinning things to it until you run out of wall, not until you run out of a predefined rectangle.
Why it suits reference work specifically
A moodboard or a shot-reference board rarely has a natural size in advance. Sometimes the right composition is four images side by side; sometimes it's forty, grouped into six clusters with room between them to show they're separate ideas. A slide-based tool forces a decision about size before the board is finished being built. A canvas defers that decision indefinitely — you zoom out to see the whole argument and zoom in to check one plate against its neighbour.
The zoom is the interface
The reason panning and zooming matters more here than in a document editor is that it replaces two separate actions — scrolling through a folder to find an image, and then arranging what you found — with one continuous motion. Zoom out to see how twelve plates relate to each other as a set; zoom into any one of them to check a detail against its neighbour without leaving the board. Nothing about that requires a fixed frame, and a fixed frame is exactly what would break it.
What differs between canvas tools
The pan-and-zoom surface is common to all of them; what varies is what's allowed to sit on it and where the file lives afterward.
- General whiteboards — Miro, FigJam, Obsidian's canvas — are built first for diagrams, sticky notes and live collaboration between several people at once, with images as one node type among many.
- Image-first canvases — PureRef, Coii Ref — are built around plates: pictures, primarily, arranged with less concern for shapes and connectors and more for scale, cropping and layering.
Where the file ends up also differs sharply. A board built in a
browser-based whiteboard usually lives in that service's account, reachable
through its app or its share link. Coii Ref writes each board as a
.coii-canvas file — plain JSON, saved in your own folder next to the images
on it — so opening it later needs nothing but the file itself.
A canvas file itself is usually invisible to the person using the app — it lives behind an account, reachable only through that service. Whether that matters to you is really a question about how long you expect to want the board: for a meeting next week it rarely does, and for a piece of visual development you'll want to reopen in three years, it's worth knowing in advance whether the file survives the account.
If you're weighing a general whiteboard against something built specifically around images, the comparison against Miro covers the trade in detail, and the built-for page shows what an image-first canvas looks like applied to a real folder of references. Or try Coii Ref directly — thirty days, no card, against your own material.