TreeLine

Free plan LinuxMacWindows

What TreeLine is

TreeLine is a free offline organizer for information arranged in a tree. Each node can hold fields that work like a small database, making the structure suitable for items such as book lists, contacts, logins, or tasks. Files can contain multiple node types with different fields and formats. Supported values include text, HTML, numbers, dates, times, Boolean values, and URLs. Users can search node data and filter matching items into a flat view. Node output can appear on screen, be printed, or be exported to HTML. TreeLine files use JSON and can be compressed or encrypted automatically. Import and export options include plain text, delimited tables, XML, ODF text outlines, and several bookmark formats. TreeLine is listed for Windows, Linux, and macOS, though macOS is not formally supported. Windows 10 and 11 installers are available; Linux installation uses the source package and requires Python 3.9 or later, Qt 6.4 or later, and PyQt 6.4 or later. The listed plan is free under GNU GPL v2 or later.

Who it suits

TreeLine suits people who want to organize varied personal information in a searchable, tree-based file. It may work for users comfortable with the listed Linux prerequisites or Windows installers.

What it does well

Free under GNU GPL v2 or later
Works offline on Windows, Linux, and macOS
Stores diverse data types in separate node types
Supports search, filtering, and many export formats
Files can be compressed or encrypted automatically

What to know first

macOS is not formally supported
Linux installation requires Python, Qt, and PyQt prerequisites
Spell checking requires an external program

Plans

Plan	Billed and limits	Price
TreeLine	GNU GPL v2 or later · no warranty stated	Free

As treeline.bellz.org lists them, read 7 Oct 2026. The maker's own page has the final word.

Getting started

Visit the TreeLine website.
For Windows 10 or 11, use the all-user or single-user installer.
For Linux, use the source package with Python 3.9 or higher, Qt 6.4 or higher and PyQt 6.4 or higher.
For macOS, the site points to a third-party MacPorts version.

Verdict

TreeLine offers a flexible tree structure for organizing and exporting information without an ongoing price. Check the platform caveats and Linux requirements before choosing it.

Questions

Is TreeLine free?

Yes. Its listed plan is free under GNU GPL v2 or later.

Which platforms does it support?

It is listed for Windows, Linux and macOS. The site says macOS is not formally supported.

Can TreeLine be used offline?

Yes, offline access is listed.

What kinds of information can it store?

Fields support plain and rich text, HTML, numbers, dates, times, booleans and URLs.

Can it import and export files?

Yes. Options include plain text, delimited tables, TreeLine files, Mozilla and XBEL bookmarks, generic XML and ODF text outlines. Listed exports also include CSV, PDF and other formats.

What is required for Linux installation?

The source package requires Python 3.9 or higher, Qt 6.4 or higher and PyQt 6.4 or higher.

Facts from TreeLine's own pages

Data types: It supports plain text, rich text, HTML, numbers, dates, times, booleans, and URLs. · treeline.bellz.org, 7 Oct 2026
File formats: TreeLine files use JSON and can be automatically compressed or encrypted. · treeline.bellz.org, 7 Oct 2026
Free plan: Yes · treeline.bellz.org, 20 Sept 2026
Import and export: It can import and export plain text, delimited tables, older TreeLine files, Mozilla and XBEL bookmarks, generic XML, and ODF text outlines. · treeline.bellz.org, 7 Oct 2026
Intended users: The site describes TreeLine as useful for organizing information such as lists of books, movies, website logins, contacts, and things to do. · treeline.bellz.org, 7 Oct 2026
Linux: Linux installation uses the source package and requires Python 3.9 or higher, Qt 6.4 or higher, and PyQt 6.4 or higher. · treeline.bellz.org, 7 Oct 2026
macOS: The site says macOS is not formally supported due to a lack of Macs for testing and points to a third-party MacPorts version. · treeline.bellz.org, 7 Oct 2026
Offline access: Yes · treeline.bellz.org, 20 Sept 2026
Organization: A file can include several node types with different sets of fields, and each node type can have its own format. · treeline.bellz.org, 7 Oct 2026
Output: Node output can be shown on screen, printed, or exported to HTML. · treeline.bellz.org, 7 Oct 2026
Purpose: TreeLine stores information in a tree structure, with fields on each node forming a mini-database. · treeline.bellz.org, 7 Oct 2026
Search and filtering: Find commands search node data, and filtering commands show matching nodes in a flat view. · treeline.bellz.org, 7 Oct 2026
Spell checking: Spell checking requires an external program: aspell, ispell, or hunspell. · treeline.bellz.org, 7 Oct 2026
Support: Doug Bell welcomes feedback, bug reports, and suggestions by email, and the site points TreeLine users to a mailing list. · bellz.org, 7 Oct 2026
Windows: The site says TreeLine should run on computers using Windows 10 or 11 and provides all-user and single-user installers. · treeline.bellz.org, 7 Oct 2026