Open source note-taking and knowledge base tools

Three kinds of tool

This category covers tools that look similar on the surface but solve different problems.

• Personal note apps keep one person’s notes in sync across devices, usually organized in notebooks or tags. Joplin, Notesnook and Standard Notes are the closest open source replacements for Evernote, and all three can encrypt notes end to end. Memos is narrower: a self-hosted timeline of short notes.
• Personal knowledge bases are about connecting ideas rather than filing them. Logseq is an outliner with block references and daily journals, SiYuan adds SQL queries and flashcards to a block editor, and Trilium Notes builds a deep note tree with many note types and scripting. They are local-first and made for a single user, which puts them in the same space as Obsidian.
• Team workspaces and wikis run on a server and are built around shared spaces and permissions. AFFiNE and AppFlowy follow Notion’s mix of documents and databases. Docmost, BookStack, Wiki.js and XWiki are documentation wikis in the Confluence tradition, from a simple book structure to a full intranet platform.

Pick the kind first. A personal knowledge base will frustrate a team that needs permissions, and a company wiki is heavy for private journaling.

How your notes are stored

The storage format decides how easy it is to leave later. The file-based version of Logseq writes plain Markdown or Org-mode files that any editor can open. Trilium, SiYuan and Logseq’s new DB version keep notes in a database and offer Markdown as an export. Team wikis store pages in PostgreSQL or MySQL; Wiki.js can also sync pages to a Git repository, and BookStack exports books as Markdown, HTML, PDF or a portable ZIP.

Encryption and sync

Notesnook and Standard Notes encrypt everything on the device by default, so their servers only hold data they cannot read. Joplin offers optional end-to-end encryption that you switch on yourself. Trilium encrypts individual notes you mark as protected, not the whole database. Team wikis are not end-to-end encrypted: the server must read pages to search and render them, so protection comes from who runs the server and its access controls.

Sync is where the licensing and business models show. Joplin can sync through Nextcloud, WebDAV or S3 storage you already have. Trilium uses its own self-hosted server at no cost. SiYuan’s sync, even to your own S3 or WebDAV storage, is a paid feature, and Logseq’s official sync is a paid service.

Read the license and the paid tiers

Several projects are open core or have closed parts, and the details change what “self-hosted” means:

1. AppFlowy: the client is AGPL-3.0, but the server needed for sync and collaboration is now closed source, and the free self-hosted tier allows one user.
2. AFFiNE: MIT for most code, but self-hosted workspaces are capped at 10 seats without a paid license.
3. Joplin: the apps are AGPL, but Joplin Server is licensed for non-commercial use only.
4. Docmost: SSO, MFA, page-level permissions and the Confluence importer are in the paid Business edition.
5. Standard Notes: premium editors and nested tags need a paid plan, even on your own server.

By contrast, BookStack, Wiki.js, Trilium and Memos have no paid edition, and BookStack and Wiki.js include LDAP and SAML sign-in.

Self-hosting effort

Memos and Trilium are the lightest: one process and a SQLite file. BookStack needs PHP and MySQL, which many hosts already run. Wiki.js, Docmost and AFFiNE use Node.js with PostgreSQL, and Docmost and AFFiNE add Redis. XWiki is the heaviest, with Java, a servlet container, a database and Solr. Notesnook’s sync server runs several services with MongoDB and MinIO and is not yet officially supported.

Leaving Confluence, Evernote or Notion

Atlassian ended support for its Server products on 15 February 2024, and Confluence Data Center reaches end of life on 28 March 2029, when instances become read-only. Organizations that need to keep wiki data on their own servers are the main audience for alternatives to Confluence; XWiki SAS offers a Confluence migration toolkit. For Evernote, Joplin, Notesnook, Standard Notes and Trilium import ENEX export files. AppFlowy and Docmost import Notion exports.

Source-available projects not listed

Two well-known tools are not listed because their licenses are not open source. Outline, a popular team wiki, uses the Business Source License 1.1, which bars offering it as a commercial document service until the code converts to Apache-2.0 on a later date. Anytype uses the Any Source Available License, which limits use to non-commercial purposes or commercial use in allowed networks. Obsidian itself is proprietary.