Self-hosted note-taking has a clear argument behind it: your notes are the most personal data you produce, and keeping them off Notion's servers, Evernote's cloud, or Google's infrastructure has genuine value. The question is how to do it without trading one set of problems for another.
Trilium Notes, Obsidian, and AppFlowy are three self-hosted approaches that solve this differently. Trilium is a hierarchical knowledge base built for depth: relations between notes, scripting, encryption, and structure closer to a personal database than a note app. Obsidian stores everything as plain Markdown files on disk, which means your data survives any company failure and works with any text editor. AppFlowy builds Notion-style block documents locally, targeting users who want Notion's feel without Notion's cloud dependency.
Which fits depends on how your brain organizes information.
Trilium Notes
TriliumNext is the actively maintained community fork of Trilium Notes, which accumulated 28,000+ GitHub stars under original developer zadam before he stepped back from maintenance in 2024. The fork has continued development with regular releases and an expanding contributor base.
The central concept is hierarchy. Notes live in a tree structure, but each note can be cloned to appear in multiple locations simultaneously: a note about a project exists in the project tree and a reference section at the same time, without duplication. Notes connect with typed relations — "inspired by", "related to", "is a subtask of" — and you can visualize these connections as a graph.
What Trilium does that neither Obsidian nor AppFlowy attempt: note encryption at rest, code notes with syntax highlighting and execution, custom scripting to automate note behavior, and a structured attribute system that turns notes into a queryable database. For someone building a personal knowledge base that tracks research threads, decisions, and project histories in linked structure, Trilium handles it without plugins or workarounds.
The sync model is clean: run TriliumNext's server on your own hardware, and every client syncs through it. No third-party cloud. No subscription. The server is a Node.js process that runs fine on a Raspberry Pi or small VPS.
Where it falls short: No mobile app. The web interface works on phones but is not designed for mobile capture. If you generate notes primarily on a phone, Trilium will frustrate you. The learning curve is also steeper than both alternatives. You need to invest time upfront building a hierarchy and attribute system before productivity improves.
Cost: $0. Self-host the sync server and every feature is available.
Obsidian
Obsidian takes the opposite approach to data. Notes are Markdown files in a folder on your computer. Open your vault folder in any text editor and every note is readable. Switch away from Obsidian and nothing is locked in; your files work with Bear, iA Writer, VS Code, or a basic terminal editor.
The app adds wiki-style links between notes using [[double brackets]] and builds a visual graph of how notes connect. The plugin ecosystem is what separates Obsidian from simpler Markdown editors: 1,000+ community plugins add spaced repetition, task management, canvas view, Kanban boards, daily notes, templates, and Dataview queries that turn note metadata into a database. You can build almost any workflow given enough plugin research.
Sync options: Obsidian Sync costs $4/month for basic (1 vault, 1 GB storage) or $8/month billed annually ($10/month billed monthly) for Sync Plus (10 vaults, 10 GB, 12-month version history). But because notes are plain Markdown files, any file sync tool works: iCloud, Syncthing (free, P2P self-hosted), Dropbox, or a shared folder. Most personal users sync for free.
Commercial use requires a $50/user/year license. Personal use is free indefinitely.
Where it falls short: Obsidian has no real-time collaboration. Multiple people cannot edit the same vault simultaneously in any meaningful way. It's a single-user tool that supports multiple devices for that user, not a team tool. If you need teammates writing in the same workspace, Obsidian isn't the answer.
Cost: $0 personal, $50/user/year commercial, $4-10/month optional sync.
AppFlowy
AppFlowy positions itself as a local-first Notion replacement rather than a pure note-taking app. Documents use a block-based editor: paragraphs, headings, checklists, toggles, embeds. Kanban boards, grid views, and calendars are built in. The overall feel is closer to Notion than to either Obsidian or Trilium.
Built in Rust and Flutter, AppFlowy opens faster than Notion's web-based desktop app. With 60,000+ GitHub stars, it has the largest community of the three. The desktop app and self-hosted sync server are free. The hosted cloud costs $10/user/month (billed annually) for teams that don't want to run their own server.
AppFlowy added real-time collaborative editing and mobile apps in 2025-2026, which puts it ahead of both Trilium and Obsidian on team workflows. If you're replacing Notion for a small team that doesn't want to pay $10-20/user/month or trust Notion's cloud, AppFlowy is the most viable option in this category.
Where it falls short: AppFlowy's data format is not portable the way Obsidian's is. Notes aren't plain Markdown files you can open anywhere — switching away requires an export step. The database relations and formula depth still lag behind Notion. Mobile apps are newer and rougher than Notion's equivalents.
Cost: $0 local or self-hosted, $10/user/month hosted cloud.
Side-by-Side
| Trilium | Obsidian | AppFlowy | |
|---|---|---|---|
| Cost | $0 self-hosted | $0 personal; $50/yr commercial | $0 local; $10/user/mo cloud |
| Sync | Self-hosted server | $4-10/mo or any file sync tool | Self-hosted or $10/user/mo |
| Data format | SQLite database | Plain Markdown files | Proprietary (local-first) |
| Portability | Export only | Full (open files in anything) | Export only |
| Mobile app | Web view only | Yes | Yes |
| Collaboration | Limited | Not designed for it | Yes (added 2025) |
| Learning curve | High | Medium | Low |
| Standout feature | Note relations, scripting | 1,000+ plugins, plain text | Block docs, Kanban |
Who Should Use Each
Obsidian is the right starting point for most people switching from Notion or Evernote for privacy reasons. The zero-cost personal tier, plain-text format, and plugin ecosystem make it the lowest-risk entry point. Add Syncthing for free cross-device sync without paying for Obsidian Sync. Your notes will be readable in 20 years regardless of what happens to the company.
Trilium is for power users who've outgrown flat-file note apps and need structured relationships between notes. Researchers, writers building long-form knowledge bases, and anyone maintaining a personal graph of decisions and projects will find features here that neither Obsidian nor AppFlowy offer. Accept the steeper setup cost and the payoff is real.
AppFlowy makes sense when you're replacing Notion for a team, not just for yourself. The block document model is familiar, collaborative editing works, and self-hosting removes the cloud dependency. For individuals, Obsidian covers more use cases more flexibly. For a 5-15 person team moving off Notion's $10-20/user billing, AppFlowy is the only realistic self-hosted option in this space.
The Recommendation
Start with Obsidian. Plain Markdown means zero lock-in, the free personal tier costs nothing, and the plugin ecosystem lets you grow the workflow over time. If after six months you find yourself wanting typed relationships between notes and a scripted knowledge graph, migrate to Trilium — the concept is different enough that starting with Obsidian first helps you understand what Trilium actually adds.
For a broader view of self-hosted options beyond note-taking, the best self-hosted apps roundup covers Home Assistant, Jellyfin, Forgejo, and others alongside the hardware decisions. AppFlowy in the context of a Notion replacement is covered in the AppFlowy vs Notion comparison, which gets into database depth, pricing math, and the specific cases where Notion still wins.