Text formats last
A plain text file (.txt) is a format that hasn’t changed in decades. Because it doesn’t depend on any particular app, you can still read it when apps change, when your PC changes, or ten years from now.
One thing to be aware of: text files have a concept called “character encoding.” TextTree supports UTF-8 and Shift-JIS, which covers the vast majority of text files you’ll encounter in everyday use.
Beyond plain text, you can also write rich documents with headings and bold, and diagrams built from cards and arrows. But none of it is saved in a proprietary format — every one is a standard file.
| Feature | File | What’s inside |
|---|---|---|
| ThinkTray (diagrams) | .tt.svg | SVG you can view as an image |
| Rich document editor | .tt.html | Self-contained HTML |
| Markdown editor | .md | Markdown |
Both HTML and SVG are human-readable text when you open them. A .tt.html file displays as-is in any browser, and a .tt.svg opens as an SVG image in any browser or image viewer. Editing a diagram again needs TextTree (or editing by hand), but what you wrote — and the diagram itself — is never locked inside one app.
Your folder structure becomes a map of your thinking
TextTree uses your PC’s actual folders as your workspace. No special database, no proprietary format needed.
Just name your folders and arrange your files inside them, and a map of your own thinking takes shape. The feeling of “that note should be in that folder” comes naturally — faster than learning how any tool works.
That “there was something in that folder” hunch usually stays unspoken. The folder viewer can show a one-line AI summary next to each folder and file (an optional feature you turn on in settings, using your own API key). It may let you pin down as concrete words what was only ever a hunch.
Staying focused on thinking
TextTree’s purpose is thinking. That is exactly why we are careful about adding features.
Tags, backlinks, databases, cloud sync — tools built around these features each have their place and their strengths. But every feature you add brings a cost to learn it and a cost to keep it tidy. The more time you spend on how to organize, the less is left for the thinking that matters.
Even with rich documents and ThinkTray added, all that grew is what sits inside “write, think, tidy.” Open the editor and write. Think in a diagram. Move files around to organize. Nothing has been added around that for you to learn or maintain.
Your words stay with you
Everything you write stays in a folder on your own PC. Even if the app disappears, your data doesn’t.
TextTree is a web app, so it does require an internet connection to load — but your data lives in a local folder, so you can open it in any editor, copy it, or move it freely. If you’re worried about backups, simply put your workspace inside a cloud-sync folder like OneDrive or Dropbox — your files will be backed up automatically.
Last year’s notes, ideas from five years ago — with plain text files, they’re always within reach. Your record of thinking quietly accumulates inside a simple folder. That’s what TextTree is built around.