The best free reference board apps (and what “free” really means)

If you paint, model, design, or write, a reference board is one of those tools you use every single day, so it makes sense to want one that doesn’t bill you monthly. The trouble is that “free” hides a lot of different meanings. Some apps are free forever. Some are free until you hit a card limit. Some are free to open but charge for the one feature you actually needed, like sync. This guide cuts through it with a plain breakdown of what each tool gives you for nothing.

We’re looking at four genuinely free (or free-core) options: DarkRef, PureRef, Kuadro, and Excalidraw. They’re very different tools, and the right one depends on whether you want a single canvas, a cross-device library, a lightweight viewer, or an open-source whiteboard.

The three kinds of “free”

Before the apps, a quick filter. When a reference tool calls itself free, it’s usually one of these:

• Free forever, full stop: the whole app costs nothing (Kuadro, the Excalidraw editor, and PureRef for personal use).
• Free core, paid extras: everything you need to build boards is free, and only power features like cloud sync or hosting a shared board are paid (DarkRef).
• Free but capped: free until you hit a limit on cards, boards, or storage, then you pay to continue (common with web moodboard tools; not covered as “free” here).

The honest question isn’t “is it free?” but “is the part I need free?” The table makes that explicit.

Free reference apps: what’s free, what’s paid

1) DarkRef: the most capable free core

DarkRef gives you the most for nothing. The free tier isn’t a teaser: it’s a complete reference board on iPhone, iPad, Windows, macOS, and the web. For free you get images, animated GIFs, rich sticky notes, folders, snap-to-grid, and non-destructive image editing (crop, rotate, flip, grayscale, one-tap background removal on Windows, iPhone and iPad, all reversible). You can paste any link, GIF, or YouTube clip and it becomes a live preview card, and you can view and join shared live boards at no cost.

What’s paid? Three things, bundled into DarkRef Pro ($1.99/month or $19.99/year): safer cloud sync across all your devices, hosting and editing real-time live boards, and saving from the Chrome extension. That’s an honest split: the board-building is free; only cross-device sync, hosting or editing a live board, and saving from Chrome cost money. See the exact split on the pricing page.

Best for: anyone who wants a real, cross-platform reference board for free and only pays if they later want sync, saving from Chrome, or to host or edit a shared board.

2) PureRef: free for personal use on desktop

PureRef is a long-time favorite of 2D and 3D artists: a clean, fast, single-canvas board you keep floating beside your art app. It’s free for personal use (pay what you want), businesses need a paid license, and it runs on Windows, macOS, and Linux.

For personal use, the honesty here is about what’s missing rather than what’s paywalled: PureRef has no mobile or iPad app, no cloud sync between devices, and no collaboration. It’s a superb solo desktop canvas and nothing more. If that’s all you need, it’s wonderful; if you want your board on a tablet or shared with others, see our best PureRef alternatives.

3) Kuadro: free and featherlight on the desktop

Kuadro is a free, extremely lightweight reference viewer for Windows and Mac. Drop images on screen, keep them on top while you work, done. There’s no cost and no catch, because there’s also not much to it beyond viewing.

It’s desktop-only (Windows and Mac), with no mobile, no sync, and only minimal organization. It’s perfect if you want the fastest possible “pin a few refs on screen” experience and nothing more. If you outgrow it and want folders, editing, or cross-device boards, our best Kuadro alternatives covers where to go next.

4) Excalidraw: free and open source

Excalidraw is a free, open-source virtual whiteboard with a hand-drawn look. The editor is completely free to use in the browser, and because it’s open source you can even self-host it. It’s great for quick diagrams, sketches, and loose visual thinking.

The caveat is that it’s a whiteboard for diagramming and sketching, not an image-reference manager. There are no folders in the free editor, no tagging, and no reference library, and richer team/cloud features live in a separate paid hosted plan. For a board built around collecting and organizing reference imagery, see our best Excalidraw alternatives.

Honest note: free has real limits

Free tools are fantastic, but it’s worth being clear-eyed about the ceiling:

• PureRef (for personal use) and Kuadro are free because they’re solo and desktop-only: there’s no server to sync across, which is exactly why they can’t.
• Excalidraw is free and open, but it isn’t trying to be a reference organizer.
• DarkRef keeps the board free and only charges for the things that genuinely cost money to run (cloud sync and live collaboration), which is the fairest split if you want those.

None of these will manage a giant, heavily tagged asset library the way a dedicated desktop asset manager does; that’s a different tool for a different job.

Which free reference board should you use?

• You want a full reference board free on every device (and optional sync later): DarkRef.
• You only work on desktop and want a proven single canvas: PureRef.
• You want the lightest possible desktop viewer: Kuadro.
• You mainly sketch and diagram, and open source matters: Excalidraw.

FAQ

What is the best free reference board app?

Of the apps here, DarkRef offers the most capable free tier: a complete reference board on iPhone, iPad, Windows, macOS, and web, including images, GIFs, notes, folders, non-destructive image editing, link and YouTube preview cards, and joining shared live boards, all free. Only cloud sync, hosting or editing live boards, and saving from the Chrome extension require Pro at $1.99/month. PureRef is the best free option for personal use if you only work on desktop.

Is DarkRef completely free?

The core app is completely free on all five platforms, and the free feature set is deep enough to use every day. Three things are paid, bundled as DarkRef Pro ($1.99/month or $19.99/year): cloud sync across your devices, hosting or editing real-time live boards, and saving from the Chrome extension. You can join and view someone else’s live board for free.

Is PureRef free?

For personal use, yes. PureRef is free to download and use on Windows, macOS, and Linux, with an optional pay-what-you-want payment. Businesses need a paid license: $49 one-time for a studio of up to 3 people, or $8 to $10 per seat per month. The trade-off is that it has no mobile or iPad app, no cloud sync, and no collaboration: it’s a solo desktop canvas.

Is Excalidraw really free and open source?

Yes. The Excalidraw editor is free and open source, and you can self-host it. It’s built for diagramming and sketching rather than managing reference images, and heavier team and cloud features are offered through a separate paid hosted plan.

Do any free reference apps sync across devices?

Among these, DarkRef is the one designed for cross-device use: its cloud sync (part of Pro) keeps the same board on iPhone, iPad, Windows, macOS, and web. PureRef and Kuadro are single-device desktop tools with no sync, and Excalidraw’s persistent cloud storage sits in its paid hosted plan.