Best Free & Open Source Alternatives to Obsidian

Memos is an open-source, self-hosted note-taking platform built for capturing and organizing thoughts quickly. Written in Go with a React frontend, it runs as a single lightweight binary and can be deployed in minutes via Docker. Every note is stored in your own database, giving you full ownership of your data without relying on third-party cloud services.

Notes are written in plain markdown with support for tags, mentions, and inline formatting. Memos includes a built-in AI assistant powered by local or remote LLMs for summarization, tagging, and semantic search, while remaining fully functional offline. The web UI is fast and minimalist, with keyboard shortcuts, dark mode, and a mobile-friendly responsive layout that works well across devices.

With an active community and 60k+ stars on GitHub, Memos strikes a balance between the structure of a knowledge base and the simplicity of a quick-capture journal. It is MIT-licensed and ideal for individuals and small teams who want a private, low-maintenance alternative to Notion, Obsidian, or Evernote.

Joplin is a free, open-source note-taking and to-do application designed with privacy at its core. It supports markdown editing and organises notes into notebooks with tags, making it easy to structure large collections of notes.

One of its standout features is end-to-end encryption combined with flexible sync options — you can sync via Joplin Cloud, Nextcloud, WebDAV, Dropbox, OneDrive, or your own server. This makes Joplin a strong self-hosted alternative to Evernote, removing the need to trust a proprietary cloud with your data.

Available on Windows, macOS, Linux, Android, and iOS, Joplin also supports a web clipper browser extension for capturing web content. It is scriptable via plugins and has an active community ecosystem, making it suitable for both casual note-takers and power users.

AFFiNE is an open-source, privacy-first workspace that merges three tools into one: a rich document editor, an infinite whiteboard, and a database-style organiser. It is designed to replace the combination of Notion for notes and Miro for visual collaboration.

Built with a local-first architecture using CRDT, AFFiNE works offline by default and syncs when connected — meaning your data lives on your device, not just in the cloud. It supports both self-hosted deployment and AFFiNE Cloud for teams that want a managed option.

AFFiNE is highly customisable and supports markdown, block-based editing, kanban views, and edgeless canvas mode for mind-mapping and diagramming. Written in TypeScript and Rust, it is actively developed and positions itself as a next-generation alternative for knowledge workers who want flexibility without vendor lock-in.

Rowboat is a local-first desktop AI coworker that indexes your work into a living Obsidian-style backlinked knowledge graph. It includes built-in work surfaces for collaborating with AI: an email client that auto-drafts responses using work context, a built-in browser isolated from your main browser, a meeting note-taker with live transcription, and a code mode for parallel coding agents.

Unlike most AI tools that reconstruct context on demand, Rowboat maintains long-lived knowledge that compounds over time. Context accumulates, relationships are explicit and inspectable, notes are editable by you, and everything lives on your machine as plain Markdown. It supports bring-your-own-model (Ollama, LM Studio, or any API), MCP tool integrations, and background agents that run on events or schedules.

SilverBullet is a powerful, markdown-based personal knowledge management tool and note-taking app optimized for people with a hacker mindset. It stores all notes as plain markdown files and extends them with a live query and template system that lets you create dynamic, database-like views within your notes.

Key features include live queries that pull data from across your note space into any note, slash commands for quick insertion of templates and snippets, a command palette, full-text search, backlinks, a rich plugin system (Plugs), and a web-based interface that works offline. SilverBullet is serverless — it runs entirely in the browser for a single user, or can be hosted on a server for access from multiple devices.

For Obsidian or Notion users who want something more programmable and self-hostable, SilverBullet's live query engine and template system provide a uniquely powerful approach to building a second brain and personal knowledge base.

Files.md is a minimal, local-first note-taking application built around plain Markdown files. Unlike complex knowledge management tools, it focuses on simplicity and portability: there is no build system, no database, and no vendor lock-in. You open web/index.html in your browser and start writing.

The app supports notes, documents, projects, journals, habits, checklists, and tasks. All data lives in local .md files that you fully own. A Telegram bot provides on-the-go access, and the server is a single binary for those who want self-hosted sync. The project is deliberately small enough that a single developer (or an LLM) can understand the entire codebase.

Compared to Notion, Obsidian, or Evernote, Files.md trades advanced features for extreme simplicity and data ownership. There are no plugins, no graph views, and no AI workflows—just plain text files that work offline and sync via iCloud, Dropbox, or Google Drive.

NoteDiscovery is an open-source, self-hosted knowledge base designed for personal note-taking and knowledge management. Built with a modern JavaScript stack and FastAPI backend, it provides a clean interface for capturing and organizing your thoughts.

The application supports markdown formatting, making it easy to write and format notes. It is designed around the Zettelkasten methodology, a powerful system for connecting ideas and building a personal knowledge network.

As a self-hosted solution, NoteDiscovery gives you complete control over your data and privacy. It can be easily deployed using Docker, making setup straightforward for users familiar with containerization. Whether you are looking to replace Notion, Evernote, or Obsidian with a privacy-focused alternative, NoteDiscovery offers a compelling option.

Alexandrie is a self-hosted, open-source knowledge management platform built for teams and individuals. It combines a powerful Markdown editor, offline support, collaboration tools, and enterprise-grade permissions.

Key Features

• Advanced Markdown Editor - Extended CodeMirror 6 environment with LaTeX, diagrams, speech-to-text, snippet manager, and custom containers.
• Team Workspaces - Multi-tenant architecture with 5-level access model (None, Read, Write, Admin, Owner), invitation codes, and team management.
• Kanban Boards - Integrated task management with Kanban boards in every workspace.
• Full-Text Search - Command center (Ctrl+K) with instant lookup, snippet highlights, and relevancy sorting.
• Offline-First PWA - Install on any desktop or mobile device with full offline capabilities and seamless synchronization.
• S3 Integration - Native compatibility with RustFS, Garage, MinIO, or AWS for media storage.
• OIDC SSO - Built-in OpenID Connect support with multiple identity providers.
• Backup & Restore - Automated full-system backup and restore pipelines.

Self-Hosting

Deploy the entire stack with a single Docker command. Alexandrie is designed for teams that want full ownership of their knowledge base without relying on third-party cloud services.

Scratch is a minimalist, offline-first markdown note-taking app built for macOS, Windows, and Linux. Unlike cloud-based alternatives, Scratch stores all your notes as plain .md files that you fully own — no account required, no internet connection needed.

It features WYSIWYG editing that saves as markdown, a preview mode for any .md file via drag-and-drop or "Open With", markdown source mode toggle, syntax highlighting for 20+ languages with a GitHub-inspired color scheme, Mermaid diagram support, KaTeX math rendering, wikilinks with autocomplete, slash commands for quick formatting, focus mode for distraction-free writing, and optional Git integration for version control and multi-device sync.

Scratch is built with Tauri, React, and Tailwind CSS, making it lightweight — 5-10x smaller than Obsidian or Notion. It also integrates with local AI tools like Claude Code, OpenAI Codex, OpenCode, or Ollama for editing notes with AI, and detects external file changes so it works seamlessly alongside other tools.

Many Notes is a Markdown note-taking web application designed for simplicity. Easily create or import your vaults and organize your thoughts right away. It uses a database to power its features, but your files are also saved in the filesystem, giving you full control over your vault structure and ensuring easy access and portability.

Vaults are simply storage containers for your files, and Many Notes lets you choose to keep all your files in one vault or organize them into separate vaults. The app supports multiple users, OAuth authentication, real-time collaboration with live-updating interfaces, and an advanced Markdown editor with automatic saving. Additional features include links, backlinks, tags for note organization, export to PDF, import/export vaults for backup, and a Progressive Web App experience for a native app-like feel.

TriliumNext Notes (a community fork of Trilium Notes) is a powerful, open-source personal knowledge base application focused on building large, hierarchical note collections. It supports rich text editing, markdown, code blocks with syntax highlighting, diagrams, relation maps, and advanced scripting via JavaScript.

Notes are organized in a tree structure, but each note can appear in multiple places through clones — a flexible approach that lets you organize information in interconnected ways. Trilium also features a powerful attribute system for tagging and templating notes, and a scripting API that enables custom automations.

For self-hosters, Trilium can be deployed as a web server and accessed from any browser. It syncs across multiple instances, supports end-to-end encryption for sensitive notes, and exports to standard formats. It is an ideal alternative to Notion or Obsidian for users who want complete data ownership and a deeply customizable note-taking system.

kuku is an open-source, local-first Markdown workspace for macOS designed for people who want their notes to stay portable, private, and useful to AI. It edits ordinary .md files in a local vault, then layers search, graph navigation, AI assistance, Second Brain workflows, and encrypted sync on top.

The app connects notes with [[wikilinks]], backlinks, and 2D/3D graph navigation, turning your vault into a personal wiki. AI features include Agent, Ask, and Inline editing modes with diff-based approval, so proposed changes are always reviewable before they are applied. Decision documents help AI context improve explicitly over time by turning proposals into traceable memory and wiki updates.

Built as a full-stack open-source project, kuku includes the macOS client, web app, Go server, protobuf contracts, Rust AI/indexing crates, and Docker infrastructure. You can use it entirely offline, sign in for managed convenience, or self-host the complete stack yourself.

OpenKnowledge is a local-first, AI-native markdown editor and LLM wiki. It provides a WYSIWYG editing experience for .md and .mdx files that feels closer to Google Docs or Notion than to a traditional text editor, while still keeping the underlying files as plain, git-trackable markdown.

The editor is built around LLM collaboration. It ships with first-class integrations for Claude (Claude Code), Codex, and Cursor, plus an MCP server, agent skills, and a CLI so any agent harness can read, edit, and search your knowledge base. Out of the box it works as a second brain and spec-driven development workspace for LLM wikis.

OpenKnowledge runs entirely on your machine. A native macOS app is available, and a Node.js-based web editor + CLI work on Linux, Windows, and Intel Macs. Team sharing and auto-sync are powered by GitHub under the hood, so there is no vendor lock-in and your notes stay in standard markdown you can open in Obsidian, VS Code, or any other tool. Compared to Notion, you get the same fluid editing and AI features without cloud storage fees or proprietary formats; compared to Obsidian, you get a more polished WYSIWYG experience and deeper agent integrations out of the box.

Jotty is a minimalist, self-hosted note-taking and checklist application built for simplicity and control. It stores notes as plain files, giving you full ownership of your data without relying on any proprietary sync service.

Designed for homelab and personal use, Jotty covers everyday productivity needs — quick notes, to-do lists, and checklists — without the complexity of feature-heavy tools like Notion. It is lightweight by design, making it easy to deploy and maintain on your own infrastructure.

With Docker-based deployment, Jotty is a practical choice for self-hosters who want a fast, no-frills notes manager that stays out of the way.

Anchor is an offline-first, self-hostable note-taking application built around speed, privacy, and reliability across web and mobile. Notes are stored locally, fully editable without an internet connection, and synced across devices when you come back online, so your data is always available and always under your control.

The app ships with a rich text editor (bold, italic, underline, headings, lists, checkboxes), custom tags with colors, image and audio attachments, customizable note backgrounds, pinning, archiving, and a soft-delete trash with a recovery period. Notes can be shared with other users on the same instance as either viewers or editors, and an admin panel handles user management, registration control, and system statistics. Authentication is handled locally or via any OIDC provider such as Pocket ID, Authelia, Authentik, or Keycloak.

Unlike Google Keep, which is locked to Google's ecosystem and account system, Anchor runs as a single Docker container (with an optional external PostgreSQL database) that you host on your own infrastructure. There is no telemetry, no vendor lock-in, and your notes never leave your server unless you explicitly share them. It is a great fit for anyone who wants Keep's lightweight feel combined with the privacy, portability, and long-term control of self-hosted software.

HelixNotes is a local-first markdown note-taking application built with Tauri, SvelteKit, and Rust. Unlike cloud-based alternatives, it stores your notes as standard Markdown files on your local filesystem — giving you complete ownership and zero vendor lock-in.

The app features a rich WYSIWYG editor powered by TipTap with slash commands, tables, and code highlighting, alongside a source mode for raw Markdown editing. You can link notes with [[wiki-links]] and explore connections through an interactive graph view. Full-text search is powered by Tantivy for instant results across your entire vault.

HelixNotes supports KaTeX math rendering, Mermaid diagrams, daily notes with a built-in calendar, version history with diffs, automatic backups, and AI writing tools via local Ollama or your own API keys. It runs natively on Linux, Windows, macOS, and Android without Electron — making it significantly faster and lighter than many competitors.