Kosshi Outliner

5.8easy start · #26 of 31
in Outliner Software

Free to practise onnot on record
Free trialnot on record
Well documentedyes
Runs where you worknot on record

Runs on iOS, Mac.

Kosshi Outliner is ranked #26 of 31 in outliner software on The Geeks Club. It runs on iOS, macOS. There is no free plan. A free trial is offered.

Kosshi Outliner plans and pricing

All plans

Kosshi Outliner $24.99 once One-time purchase; no subscription 7-day free trial · Trial switches to read-only mode · App Store purchase unlocks all features kosshi.app · 7 Oct 2026

Compared on outliner software

Free plan: No
App platforms: macOS, iOS (iPhone, iPad)
Export formats: Markdown, Rich Text, TextBundle, Plain Text, OPML
Offline access: Yes
Markdown support: Yes
Real-time collaboration: No
Backlinks: Yes
Navigation modes: collapse, zoom, search, filters, bookmarks, saved searches

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The record

Purpose: Kosshi is a personal outliner for gathering notes, thoughts, and tasks across projects.
Outline model: Everything goes into a single outline that users organize with indentation, row movement, collapsing, and search.
Editing: The app supports Markdown formatting, checkboxes, keyboard shortcuts, and zooming into a row and its children.
Files and export: Users can add images, PDFs, and videos to an outline and export as Markdown, OPML, or plain text.
Scale: Kosshi says its rendering and data structures are designed to keep outlines usable beyond 100,000 rows.
Integrations: Dated @tags can sync with Apple Reminders or Calendar; Kosshi also syncs outlines across Apple devices through iCloud CloudKit.
Storage: Outline data is stored in a local SQLite database on each device, with optional sync through a private CloudKit database in the user's iCloud account.
Security: The developer says it has no server-side access to users' private CloudKit records and does not currently support end-to-end encryption through Advanced Data Protection.
App privacy: The app does not collect analytics or usage data, and the developer says it does not collect, transmit, or access users' app data.
Collaboration limit: Shared outlines and collaboration are not supported.
Platform limit: Kosshi runs on macOS and iOS, and the FAQ says there is no Windows or Android version planned at this time.
Trial limit: After the seven-day trial, the app switches to read-only mode until a one-time purchase unlocks its features.
Support: Users can contact the developer about problems, and the site also provides a forum for release discussions and feedback.
Maker: Kosshi is a solo project by Junichi Sato, who goes by Shirokuma.

Where it ranks on The Geeks Club

Best Outliner Software in 2026#26 of 31

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Sources

kosshi.app/why-i-built· checked 7 Oct 2026
kosshi.app/guide· checked 7 Oct 2026
kosshi.app· checked 7 Oct 2026
kosshi.app/faq· checked 7 Oct 2026
kosshi.app/todo-reminder· checked 7 Oct 2026
kosshi.app/data-privacy· checked 7 Oct 2026
kosshi.app/privacy· checked 7 Oct 2026