Quick take (read this first)
The idea in two sentences. Obsidian keeps your knowledge as plain Markdown files on your own disk, linked into a personal graph, extended by a huge plugin ecosystem. Dim0 puts notes, sketches, code, and a board-aware AI agent on a shared infinite canvas that syncs in real time.
Where Dim0 wins
- Real-time multiplayer. Obsidian is fundamentally single-player (Sync is for your own devices, not co-editing).
- AI is native, not a plugin: an agent that reads the board, searches, runs code, and writes results back as nodes.
- A spatial canvas with every node type (notes, shapes, code, charts, mini-apps), not just linked documents.
- Opinionated and ready out of the box: the canvas and the AI are built in, versus Obsidian's assemble-it-yourself plugin box (whose visual features are secondary bolt-ons).
- Runs in the browser, nothing to install, and still open-source and self-hostable with Markdown export.
Where Obsidian wins
- Local-first and offline. Your notes are files on your machine. No account, no cloud dependency, works on a plane.
- A massive plugin ecosystem and deep personal-knowledge-management workflows (backlinks, graph view, dataview, spaced repetition).
- Zero vendor lock-in in the strongest possible sense: it's just a folder of Markdown.
- Free to use, and as of 2026 that includes work/commercial use (the old commercial license is now optional). A fiercely loyal community.
Pick Dim0 if you collaborate, you want AI that acts on your work, and you think spatially. Pick Obsidian if local-first, offline, single-player PKM with total file ownership and plugins is the priority. That's a real, valid priority, and Dim0 does not try to be that.
The honest framing
Notion and Excalidraw are close comparisons for Dim0. Obsidian is a more interesting one, because it optimizes for something Dim0 deliberately doesn't: your files, on your machine, forever, alone. So this isn't a "we win" piece. It's a "here's the fork in the road" piece. If you're an Obsidian purist, read the "where Obsidian wins" section and take it seriously.
What Obsidian is (fairly)
Obsidian is a local-first Markdown knowledge base. Notes are .md files in a
folder you control. You link them with [[wikilinks]], visualize the result as a
graph, and extend the app with a plugin ecosystem that is genuinely enormous
(dataview, templater, spaced repetition, and thousands more). There's a Canvas
feature for spatial arrangement, and paid add-ons for multi-device sync (Sync,
around $4/user/month) and web publishing (Publish, around $8/site/month). The app
itself is free, and as of 2026 that includes commercial use. It is, for many
people, the most trustworthy place to keep a lifetime of notes precisely because
there's no cloud in the loop.
What it is not built for: real-time collaboration (Sync moves files between your own devices, it isn't co-editing) and native AI (that comes via plugins, bolted on).
What Dim0 is
Dim0 is a real-time collaborative thinking canvas with AI built in. An infinite board holds Notion-grade notes, freehand shapes, code, charts, docs, nested boards, and generated mini-apps, and a board-aware agent reads that board before it acts. It's web-based, runs 8 AI models, and is open-source (MIT) and self-hostable, with notes stored as plain Markdown so you can still walk away with your content.
The philosophies rhyme on openness and Markdown, and diverge hard on local-first-single-player (Obsidian) vs cloud-collaborative-AI-native (Dim0).
Opinionated canvas vs open box
Obsidian's superpower is that it's an open box: unopinionated, endlessly extensible, yours to shape. The catch is that the powerful Obsidian everyone raves about (the dataview dashboards, the templater automations, the elaborate "second brain") is a system you assemble yourself from plugins and config. Writing a note takes five minutes; building the workflow is a project. That's the real learning curve. It isn't the editor, it's the paradox of choice. Dim0 takes the opposite bet: opinionated. The canvas is the interface, the agent is built in, and every node type works out of the box, so you get value without assembling a toolchain.
And on visual thinking specifically, be precise: Obsidian isn't blind to it. It ships a Graph view and a Canvas. But both are secondary, single-player, AI-less bolt-ons. The Graph view visualizes your links and tends to become a pretty hairball at scale rather than a genuine thinking aid; the Canvas lets you arrange note cards with basic connectors, but with no real-time collaboration and no agent acting on it. Obsidian's native mode is text and links. Dim0's native mode is the spatial canvas, with AI on it. If your thinking is visual, that difference is the whole ballgame.
Head to head
| Dim0 | Obsidian | |
|---|---|---|
| Storage model | Cloud (self-hostable) | Local files, your disk |
| Offline | No (web app) | Yes (its whole point) |
| Real-time collaboration | Yes | No (Sync = your devices) |
| AI | Native board-aware agent | Via plugins |
| Spatial canvas | Yes (every node type) | Canvas feature (arrange notes) |
| Freehand / code / mini-apps | Yes | Limited / plugin |
| Plugin ecosystem | No (young) | Massive |
| Graph view / backlinks | Partial | Best-in-class |
| Data format | Markdown | Markdown files |
| Open source | Yes (MIT) | No (free, not OSS) |
| Cost | Free tier | Free (incl. commercial) |
Where Obsidian is genuinely better (take this seriously)
- Local-first ownership. Files on disk, offline, no account. Nothing beats it for "I want my notes to outlive any company."
- PKM depth. Backlinks, graph, dataview queries, years of workflows the community has built. Dim0 is not a personal-knowledge-management tool.
- Plugins. If your workflow depends on a specific plugin, Dim0 won't have it.
- Single-player focus. No collaboration overhead, no cloud, just you and your vault.
If those are your top priorities, use Obsidian. Genuinely.
Where Dim0 pulls ahead
The moment your work becomes shared, visual, or AI-assisted, Obsidian's local-first single-player model becomes the constraint:
- Real multiplayer. Bring a team onto the same board with live cursors and conflict-free edits. Obsidian can't co-edit.
- AI that acts, natively. Not a plugin summarizing a note, but an agent that reads the whole board, runs code, and builds on it.
- A true canvas, not just arranged notes. Shapes, code, charts, and mini-apps as first-class nodes.
And you still keep the parts Obsidian users care about: Markdown notes, open source, self-hosting.
So which should you use?
- A private, offline, lifelong second brain that's just your files: Obsidian.
- A collaborative, AI-native canvas where a team (or you) thinks in space: Dim0.
- They can even coexist: think and collaborate in Dim0, export the Markdown into your Obsidian vault as the permanent archive.
Different tools for different jobs. If your notes are a solo, offline vault, Obsidian is home. If your thinking is shared, spatial, and AI-assisted, that's Dim0.
Try it: app.dim0.net: open-source, self-hostable, your notes stay Markdown.
