Export is a property of your work, not the product
Tools change. Companies get acquired, pricing shifts, a product you rely on stops being maintained, or your own needs move. None of that has to be a crisis if the material you built can leave in a form something else can read.
There is a second, quieter benefit: a tool that makes leaving easy has to keep you by being good. That is a healthier relationship than one held together by the cost of getting out.
What a good export actually contains
What the common formats keep and drop
Markdown is widely readable and preserves text and basic formatting. It represents hierarchy as indentation or headings, which usually survives, and it has no standard place for dates, references or completion state.
OPML is built for outlines and carries nesting, order, notes and checkbox state well. It has no standard for dates, styling or cross-references, so those are typically lost in transit between tools.
JSON or a tool's own backup format usually keeps everything, because it was designed to. The catch is that only that tool reads it — excellent as a safety net, useless as a bridge.
PDF and HTML preserve appearance and lose editability. They are archival, not portable in the sense that matters here.
Test the export on day one
Be realistic about what portability can be
No format carries everything. Features that are specific to a tool — a particular kind of link, a live reference, a view configuration — usually have nowhere to go, and pretending otherwise sets you up for a bad surprise.
The honest goal is not lossless transfer. It is knowing in advance which parts are portable and which are conveniences you would rebuild. A tool that tells you that plainly is doing you a favour.
How this works in TreeNote
TreeNote reads and writes OPML in both directions, carrying text, notes, checkboxes, checked state and hierarchy — and dropping dates, mirrors, colour and collapsed state, which is stated plainly rather than discovered later. A TreeNote JSON backup keeps all of it for moving between your own devices. Because the workspace is local-first, the file is on your device whether or not you ever press export.
Questions
Test the exit before you need it.
Export one real branch today and read what comes out. It takes five minutes and settles the question.
Put these ideas into practice
TreeNote provides a fast, flexible outliner built around these principles. No sign up required to start.