Best open-source alternatives to Microsoft OneNote

Memos is an open-source, self-hosted note-taking application designed for quick capture and lightweight personal knowledge management. It is aimed at users who want a simple, timeline-first interface for creating Markdown notes without the overhead of folders or complex organization. The project emphasizes portability and self-hosting: notes are stored in Markdown, the app can be deployed with a single Go binary or via Docker, and it supports SQLite, MySQL, and PostgreSQL. It also presents itself as extensible through documented REST and gRPC APIs, making it suitable for integrations and custom workflows.

Joplin is an open source note-taking and task management application aimed at people who want to organize a large volume of notes in notebooks and work with them in Markdown. It supports searching, tagging, editing, and importing content from Evernote or plain Markdown files, making it useful for users migrating from other tools or maintaining text-based note libraries. The project is designed with an offline-first approach, so data remains available on the user’s devices even without internet access. For those who want cross-device synchronization, Joplin can securely sync with cloud services such as Nextcloud, Dropbox, OneDrive, and Joplin Cloud using end-to-end encryption. It also offers full-text search, customization through plugins and themes, and companion apps across major desktop and mobile platforms.

SiYuan is a personal knowledge management system designed around privacy and local control. It targets individuals who want to organize notes and knowledge using block-based editing, fine-grained references, and a Markdown-based WYSIWYG workflow rather than a traditional document-only model. The project emphasizes a broad feature set that includes large-document editing, databases, flashcards, export options, snippets, OCR, and an API for extension and integration. It also has a wider ecosystem of companion apps and components for mobile, desktop, marketplace content, and data repositories, suggesting it is aimed at users who want a cross-platform knowledge workspace with both local and deployment-oriented options.

Logseq is an open-source knowledge management and collaboration platform aimed at people who want a privacy-focused way to organize notes, tasks, and related information. It supports common note formats such as Markdown and Org-mode, and it emphasizes user control, longevity, and extensibility through plugins and themes. The README presents Logseq as suitable for students, professionals, and anyone managing personal or team knowledge workflows. It is available as a desktop application, has a web version for testing the DB version, and includes mobile apps. The DB version adds graph-based data, a new sync approach called RTC for real-time collaboration, and automated or SQLite database backup guidance because the feature set is still in beta/alpha.

Trilium Notes is a cross-platform note-taking application aimed at people who want to build and manage large personal knowledge bases. It organizes content into deep hierarchical trees and supports placing a note in multiple locations, which makes it useful for structuring related information without duplicating it. The project positions itself as free and open source, with desktop, browser, and mobile access options. The application combines a rich editor, code note support, search, versioning, encryption, scripting, and visual note types such as maps and canvas sketches. It also supports synchronization through a self-hosted server, sharing notes publicly, and automation through a REST API. The README mentions OpenID and TOTP-based login, a mobile frontend, and third-party Android/iOS clients for offline use and server sync.

Blinko is an AI-powered note-taking project aimed at individuals who want a fast way to capture short ideas and organize them for later retrieval. It presents itself as a self-hosted, privacy-conscious tool where notes are stored in the user's own environment rather than on a third-party service. The project emphasizes quick capture, Markdown formatting, and AI-assisted retrieval using RAG so users can search their notes with natural language. It also highlights broad platform support through a lightweight Tauri-based architecture, and the README points to an online demo plus hosted deployment options such as PikaPods and ZimaOS.

TiddlyWiki is a personal web notebook and interactive wiki designed for people who want a flexible, self-contained place to store and organize information. It can be used as a single HTML file in the browser, which makes it portable and easy to keep for long-term use, or as a Node.js application for more advanced client/server setups. The project is aimed at users who want a highly customizable note-taking and knowledge-management tool, as well as developers who want to extend or adapt the interface. Its UI is built in WikiText, allowing the whole application to be modified in a hackable way. The README also points users to a live demo, community forums, and developer documentation.

Standard Notes is an encrypted note-taking application aimed at people who want a secure, durable place to store notes, files, and other important writing. It emphasizes privacy through end-to-end encryption and cross-device sync, and it presents itself as suitable for both personal use and professional workflows. The project also supports self-hosting and a web-based deployment path, allowing users to run the web app from static files behind their own server. Beyond note taking, it includes publishing capabilities through Listed and supports third-party extensions/plugins, making it more than a basic notes app. The README positions it as a platform for long-term, private writing and publishing rather than just a simple editor.

SilverBullet is a self-hosted personal knowledge management platform aimed at users who want a browser-based workspace for notes, writing, and lightweight knowledge organization. It presents content as Markdown pages in a “Space,” and combines note-taking with wiki-style linking, outlining, task management, and simple database-like objects and queries. The project is especially suited to people who want more than a static markdown editor: it includes a programmable layer based on Lua for generating content and building custom commands, templates, and widgets. The README also indicates that SilverBullet has both a frontend and backend, with the client written in TypeScript and the server in Go, and it can be built and run locally or packaged into a Docker container.

flatnotes is a self-hosted note-taking web app aimed at users who want a simple, distraction-free way to manage markdown notes. It avoids a traditional database and instead stores content directly as files in a folder, which makes the notes portable and easy to edit outside the app. The project focuses on a clean interface with features such as search, tagging, markdown editing, wikilinks, and theme customization. It is designed for people who want a lightweight personal knowledge base that can be run locally or self-hosted, with support for several authentication modes and a REST API for integration.