6 open-source note apps to consider in 2026: how to choose and what to check

What is an open source memo app?

An open-source (OSS) note app is developed under a license, such as GPL, AGPL, or MIT, that makes its source code public and lets anyone inspect, modify, and redistribute it. There are 3 practical benefits.

• Verifiable — A third party can check with code whether it is really encrypted and whether there is any unnecessary communication.
• Continuity - Even if the developer is finished, volunteers can fork and continue development if the code remains. It is a strong insurance against accidents in which notes disappear due to the end of service (Captio example, LINE Keep example).
• Lock-in avoidance — Many OSS notes are saved in open formats such as Markdown, making it easy to migrate to other tools.

As a note, "open source = free" is not necessarily. Even if the app itself is OSS, models with paid official synchronization services (Joplin Cloud, Standard Notes's higher plans, etc.) are common.

Comparison table: Major open source memo apps 6 selection

※The license and form of provision are subject to change. The "final release" in the table is the public information of each official repository (GitHub) as of July 2, 2026. Please check with the latest license notation before introducing it.

Features and orientation of each app

Joplin - For those who want "OSS version Evernote"

It is the first OSS memo in terms of synchronization of notebooks, tags, web clippers, and E2EE, and the comprehensiveness of functions. Imports from Evernote are also supported. On the other hand, the UI is somewhat rugged, and you need to choose the settings of the synchronization destination (Joplin Cloud/Dropbox/self-WebDAV, etc.) yourself.

Logseq - For those who think with outliners and two-way links

It is a type that accumulates bullet points in the local Markdown/Org file and links pages to each other. While it is based on the operation of the journal (date page) and is compatible with Zettelkasten knowledge management, comfort and synchronization on mobile require ingenuity compared to desktop.

Standard Notes — To those who prioritize E2EE

All notes are encrypted end-to-end as standard, and it is a privacy-specific type. The free plan is mainly plain text, and rich editing functions are included in the paid plan. It is designed to respond head-on to the request of "I want to verify the entire encryption mechanism" (What is E2EE encryption).

Memos - For those who want to accumulate tweet-type notes in self-hosting

It is a timeline-type lightweight memo that can be used on your own server (Docker, etc.). On the other hand, you can put the data completely under your control, and you will bear the operating costs of building and maintaining the server yourself. It is popular for engineers' "distribution" usage.

Simplenote - For those who want to synchronize all terminals for free in a simple way

It is divided into text only and tags only, and synchronization is also free. The source code of the client app is made public, but The synchronous server side is private so it is not "complete OSS" (comparison with Simplenote).

Zettlr - For those who write papers and long sentences on the desktop

This is a Markdown editor for writing and academic purposes with Zotero collaboration and citation management. Since there is no mobile app, you will need another entrance to take notes on your smartphone.

Are Obsidian and Anytype open source?

The most common misunderstanding in this context is "Obsidian=open source". The Obsidian body is proprietary (non-OSS), and it is a model that is free for personal use. However, because the data is stored as a Markdown file in the terminal, it has an OSS-like beauty of "ease of taking out data". If you value "the file is at your fingertips" rather than the verifiability of the code, Obsidian is a realistic option (comparison with Obsidian).

Anytype is also sometimes referred to as "open source", but although the code is exactly public, it is Source Available (Any Source Available License) that is not an OSI-certified license. If you are concerned about the details, please check the original license (comparison with Anytype).

How to choose an open source memo app and precautions

1. See if the development is active. OSS's strength is that it can continue even if the author leaves, but it depends on the community whether it will actually be taken over. Let's check the last update date, release frequency, and response to the issue of the repository.
2. Do not automatically think of "OSS = safety". The fact that the code is published and that the encryption is valid is a different matter. Check the presence or absence of E2EE (Joplin and Standard Notes are supported, Simplenote is not supported) and how to manage the key in the specification ( Security comparison of the memo app).
3. Estimate the time and cost of synchronization. Self-synchronization (iCloud・Dropbox・Git・WebDAV) is free, but requires setup and maintenance. Official synchronization is easy, but many of them are chargeable. If "I want to use it for free" is the motivation, let's compare it with the total cost including synchronization ( free memo app ranking).

Is SimpleMemo open source? ( Honest answer)

No, the source code of SimpleMemo is private. On top of that, we respond to the "verifiable possibility" that those who consider OSS value in the following ways.

• The destination for the memo is "your email inbox" — It will be delivered as a regular email, not in your own format. Even if you delete the app, the received note will remain in your inbox.
• Do not store the body of the note on the SimpleMemo server — Only via the time of transmission, and the data waiting for transmission in the terminal is encrypted with AES-GCM-256 (AES-GCM). We have released specifications, including the fact that it is not E2EE.
• Speed measurement method is released - Anyone can verify how to measure "start 0.4 seconds" on measurement method page.

You can leave detailed organization to open-source tools such as Joplin or Logseq, while using SimpleMemo as the entry point for capturing a thought. Its measured warm launch was 0.4 seconds on iPhone 16e. This combination can fit naturally into an open-source workflow.

FAQ

What do you recommend for an open source memo app?
classics are Joplin (multifunction, compatible with all platforms), Logseq (outliner type, local first), and Standard Notes (E2EE standard) 3. If you want to use it lightly with self-hosting, Memos, if you want to use it simply, Simplenote (the client is OSS), and Zettlr is a candidate for writing on desktop.

Is Obsidian open source?
No, the Obsidian itself is not open source (it is free proprietary software for personal use). However, since the data is stored as a Markdown file in the terminal, it is easy to take out the data even if you change the app, so it has the "less lock-in" expected from the OSS.

Is SimpleMemo open source?
No, the source code of this app is private. Instead, the transmission waiting, history, and draft in the terminal are encrypted with AES-GCM-256 and the memo text is not stored on the SimpleMemo server, the method of measuring the startup speed is published, and the destination of the memo is not a specific app but an open place called "your email inbox". We emphasize transparency that can be verified.

Related articles: Ranking of free memo apps 2026 / Security comparison of memo apps / Comparison with Joplin / Comparison with Logseq