Obsidian alternatives in 2026, and which one fits working with AI agents

If AI agents write part of your knowledge base, our pick is Knowtarium: every change an agent makes waits for your approval, and an agent checks your own edits against everything connected. It's our app, and it's in pre-order, not released yet.

For other needs, the right Obsidian alternative depends on what you're missing:

• Open source and plain files: Logseq if you think in outlines, Zettlr if you write papers and long documents.
• A shared team workspace with databases: Notion.
• Local-first and encrypted, with phone apps: Anytype, or Joplin for simpler notes synced to storage you choose.
• Structure and AI built in: Capacities or Tana Outliner.
• Thinking on whiteboards, for research and study: Heptabase.

Obsidian stores your notes as plain markdown files in a folder on your computer. It runs on macOS, Windows, Linux, iOS and Android, and it's free for personal and commercial use. Those are good reasons to stay. When people look for an Obsidian alternative, it's usually for one of these reasons.

Sync costs extra

The app is free, but Obsidian Sync costs $4 per user a month billed yearly, or $5 month to month. Publishing notes as a website is $8 a month per site, billed yearly. You can sync the folder yourself with iCloud, Dropbox or git instead, but then setting it up and keeping it working is on you.

Much of the power comes from community plugins

Obsidian has thousands of community plugins, and many vaults depend on a few of them. They're built by the community, so each one is maintained on its author's schedule. Obsidian's own plugin security page says plugins can access files on your computer and connect to the internet, and that Obsidian "cannot reliably restrict plugins to specific permissions or access levels." Obsidian scans every plugin version, and for sensitive data it suggests an independent security audit before you install one.

You design the structure yourself

A new vault is an empty folder. Folders, links, tags, templates and properties give you a lot of freedom, but the system is yours to design and keep tidy. Some people would rather start from a tool with structure built in: databases in Notion, object types in Anytype and Capacities, supertags in Tana Outliner.

There's no AI built in

Obsidian doesn't include an AI assistant. You can add one with a community plugin, or point an agent at the vault folder. Since version 1.12, Obsidian also has an official command line tool that it says can "give agentic tools the ability to interact with your vault." What it doesn't do is record which notes an agent wrote, or whether anyone checked them.

It isn't open source

Its plugin API is open, but the app's own code isn't released under an open source license. If that matters to you, Logseq, Joplin and Zettlr are open source.

One reason that no longer applies: you don't need to pay to use Obsidian at work. Its commercial license is optional.

The same seven questions for every tool, with Obsidian in the first row for reference. "Coding agents" means how an agent like Claude Code or Codex reaches your notes: directly on the files, or through an MCP server, command line tool or API the app provides.

Checked on September 26, 2026, against each vendor's own site, docs and pricing page. Prices are in US dollars unless noted, per person, and shown per month when billed yearly. Prices and plans change often, so check the vendor's page before you buy. Knowtarium is our app and isn't released yet. All other product names and trademarks belong to their owners, and Knowtarium isn't affiliated with any of them. Spot something out of date? Email contact@magentix.studio.

Knowtarium is the pick for knowledge your AI agents write. It's also our app, and it isn't released yet: it's in pre-order. Weigh this entry with that in mind.

It's a desktop app (macOS, Windows, Linux) for a knowledge base that you and your AI agents write together. It opens OKF bundles: folders of plain Markdown files whose frontmatter records who wrote each document (generated), who checked it (verified), where its claims came from (sources), and when it goes stale (stale_after). OKF, the Open Knowledge Format, is an open specification published by Google Cloud.

Knowtarium doesn't call an AI itself. The agents you already use, like Claude Code, Codex and Cursor, work directly on the files, and an included skill teaches them the conventions. Chat apps can connect through an optional local MCP server. Review works both ways: an agent's change waits in the review queue as a diff until you approve it, and your own edits wait until an agent checks them against everything connected. Every change is kept in the history, stale documents are flagged, and a graph colours each document by its trust tier, up to fully verified. See the features and how agents connect.

Best for

Knowledge your AI agents write, when you need to see who wrote what and check it before anyone relies on it.

Falls short

Not released yet. No mobile app, no sync service, no plugins, and not open source. If you mostly write notes yourself, Obsidian's editor is the better fit.

Price

$20 once, or $10 during pre-orders. No subscription, no free tier or trial, no account. One personal license covers up to 2 computers. Pricing.

Coming from Obsidian, a free migration skill turns your vault into an OKF bundle. The files stay plain Markdown, so Obsidian can still open them and you can use both on the same folder. More detail: Knowtarium vs Obsidian.

Logseq is an open source (AGPL-3.0) knowledge base built around outlines: every page is a list of blocks you can nest and link, with daily journals and tasks. The established version keeps your graph as Markdown or Org-mode files in a folder, close to how Obsidian stores notes.

A new database version is in beta, and Logseq's own README warns that "data loss is possible" in it. If you want files that coding agents can read, stay on the file-based version for now.

Best for

People who think in outlines and want open source with plain files.

Falls short

Pages are saved as outlines, so they read differently in other editors. The next version is in beta, and there's no AI built in.

Price

Free. Sync is in alpha, open to monthly backers on Open Collective, from $5 a month.

More detail: Knowtarium vs Logseq.

Notion is a cloud workspace of pages, databases and wikis that a whole team shares, and the usual answer when someone leaves Obsidian to collaborate. Notion AI is built in, with full use on the Business plan, and a hosted MCP server lets Claude Code, Cursor or Codex search, read and update your workspace.

Best for

Teams that want shared databases and wikis in one place and don't need local files.

Falls short

Your content lives in Notion's cloud, not in files on your disk; Markdown and CSV are exports, not how you work day to day. Full Notion AI needs Business; Free and Plus include a trial.

Price

Free plan. Plus is $10 per member a month billed yearly ($12 monthly). Business is $20 per member a month billed yearly ($24 monthly).

More detail: Knowtarium vs Notion. For a knowledge base shared as files in git (Knowtarium itself has no team features), see the company brain.

Anytype is a local-first workspace built from objects, types and relations. Your vault is encrypted on your device and syncs peer to peer or through Anytype's network, with apps for iOS and Android. The code is published under the Any Source Available License 1.0: you can read it, but it isn't a standard open source license.

Agents reach it through the desktop app's local API, an official MCP server and an agents' skill. There's no built-in assistant yet: in its February 2026 update, the team called a local agent it's prototyping "early and experimental."

Best for

Notion-style structure with your data encrypted on your own devices.

Falls short

Notes are objects in Anytype's own storage, not files another editor can open, so agents go through its API. You can export to Markdown, PDF or HTML.

Price

Free, with 100 MB of remote storage. Plus is $4 a month billed yearly (1 GB), Pro $8 (10 GB).

Capacities organises notes as objects of a type, like a book, a person or a meeting, each with its own properties. Changes are saved on your device and synced to its cloud; its docs say it's "not about having your notes stored locally as files on your device." Pro adds an AI assistant and connectors (in beta) that let ChatGPT, Claude, Cursor and other MCP clients search, read and add to your space.

Best for

Structure by type without designing it yourself, on macOS, Windows, Linux, iOS, Android and the web.

Falls short

No folder of files for an agent or another editor. Export gives you Markdown with properties as front matter. AI and MCP connectors need Pro.

Price

Free plan. Pro is $9.99 a month billed yearly ($11.99 monthly).

Tana Outliner is an outliner where a supertag, like #meeting or #book, adds fields to any node. It has AI chat and transcription on AI credits, desktop apps with an offline mode, and apps for iOS and Android. The desktop app runs a local MCP server for Claude Code, Cursor and Codex CLI, free on every plan.

Tana Inc. also sells a separate product called Tana, an "agentic meeting platform," so make sure you're reading the Tana Outliner pricing page.

Best for

Structured notes and AI in one app, if you're fine with a cloud-synced graph.

Falls short

Your graph lives in Tana's cloud; you can export it as Markdown or JSON. Two products under one brand make plans harder to compare.

Price

Free plan with 500 AI credits. Plus is $8 a month billed yearly, Pro $14.

Heptabase is a visual knowledge base for students and researchers: notes are cards you arrange on whiteboards, next to PDFs you highlight. It includes an AI agent (Gemini models on Pro; GPT, Claude and Gemini on Premium) and runs on macOS, Windows, Linux, iOS and Android. Claude Code and Codex can edit cards and whiteboards through the Heptabase CLI while the desktop app runs, and an MCP server connects chat apps.

Best for

Research and study, when you think best by laying ideas out side by side.

Falls short

The pricing page lists paid plans only, after a 7-day trial. Notes aren't plain files: you export them as Markdown, and Heptabase notes that other apps may not keep your whiteboard layouts.

Price

Pro is $8.99 a month billed yearly, Premium $17.99.

Joplin is an open source note app for Windows, macOS, Linux, Android and iOS. You write in Markdown or a rich text editor and sync with end-to-end encryption through Joplin Cloud, Dropbox, OneDrive or Nextcloud. Joplin 3.7, released on August 31, 2026, added AI features in beta on desktop: chat, semantic search and a built-in MCP server. You choose the provider, including a model running on your own machine.

Best for

Free, open source notes with encrypted sync to a service you choose, on every platform.

Falls short

Notes are kept in Joplin's local database rather than as a folder of files, so a coding agent reaches them through the MCP server or an export. The AI features are new and marked beta.

Price

Free. Joplin Cloud starts at €2.40 a month billed yearly (€2.99 monthly).

Zettlr is a free, open source (GPL-3.0) Markdown editor for academic and long-form writing. Your files stay where you put them. It works with Zotero, JabRef and Juris-M for citations and exports through Pandoc. Since the files are plain Markdown, any coding agent can work on them.

Best for

Academic and long-form writing on plain files, with citations.

Falls short

Desktop only (Windows, macOS, Linux), and no AI features in the app.

Price

Free, supported by donations.

If agents like Claude Code, Codex or Cursor will write part of your knowledge base, three things matter more than the editor.

1. Plain files the agent can reach

Coding agents are at their best reading and editing files. Knowtarium, Obsidian, Logseq's file graphs and Zettlr keep notes as Markdown in a folder, so an agent can work on them with no setup, and you can put the folder under git. Notion, Anytype, Capacities, Tana Outliner, Heptabase and Joplin keep notes in their own storage and give agents a door instead: an MCP server, a command line tool or an API. That works, but the agent can only do what the door allows.

2. Provenance: who wrote this, and from what?

Once agents write, you need to tell their documents from yours, and know where each claim came from. In a general note app, you track that yourself with tags or properties, and every agent has to follow your convention. OKF makes it part of the format: generated for who wrote a document, verified for who checked it, sources for citations, and stale_after for when it needs a refresh. Because it's written down in an open spec, any agent can follow it.

3. Review before anyone relies on it

Agents can be wrong and sound sure. A setup you can trust shows every agent change as a diff and holds it until a person approves it. It also checks a person's edits against related documents, so they don't drift apart. You can build part of this yourself with git and pull requests on a folder of Markdown. Knowtarium builds it in, with a review queue and trust tiers on every document.

A practical path from Obsidian: keep writing in Obsidian, and let Knowtarium handle review for the documents agents maintain. Start with the guide to migrating an Obsidian vault. For the agent side, see Claude Code as a second brain, the LLM wiki and the AI second brain.