aster.

Free online mind mapping

A little thought.
A world of possibility.

Aster is a free mind-mapping tool for brainstorming and planning. Connect ideas, collect notes, and turn a wandering thought into a plan.

Start mapping

Already know your way around? Bookmark /go.

Explore Aster’s mind-mapping features

The real workspace · Seven things to try
Opening the sample workspace…

Explore the workspace

Start with one thought.

Double click a node to name it. Use Add a thought, or press Tab, to grow a child branch. Enter adds an idea alongside it.

The real workspace, brought to life with guided motion and sample ideas. Pause or choose any chapter to explore at your own pace.

Bring your own AI

A fresh perspective.
You keep the pen.

Expand a branch, find missing questions, polish wording, or reorganise a tangle of ideas—with the assistant you already use.

  1. Give it the right context.

    Select a branch, open Edit (or the node menu on mobile) → AI assistance, and choose a task. Aster prepares a prompt with the branch, map title, and path.

  2. Take it to your assistant.

    Paste the prompt into your preferred AI service and copy its reply. You choose what to share; Aster makes no automatic AI requests and needs no API key.

  3. Bring the useful parts home.

    For editing tasks, choose AI assistance → Paste a reply, review the proposed changes, then Apply. Plain outline replies can be pasted onto a selected node to add child ideas. Undo is always available.

Only share information you are comfortable sending to your chosen provider. Its account requirements and privacy terms apply. The tour uses a prepared example, not a live AI response.

Your first five minutes

From “what if”
to what’s next.

1

Put the first idea down.

Open the workspace and double click the central idea to rename it. Add branches with Tab and ideas alongside them with Enter. On your phone, use the add buttons.

2

Arrange it until it makes sense.

Drag a node onto another to nest it. Use the outline for a list view, fold the detail away, or focus on one branch. Drag the background to explore; use Fit to see the whole map.

3

Keep a copy of your thinking.

Choose Save map to keep a file you can reopen with Open. Your map file includes its notes and note board. You can also export a Markdown outline from the More menu.

A note from the maker

Why I made this.

Stefan MokrosCreator of Aster

A little space to think.
A little more room for possibility.

I made Aster to help people untangle a problem, explore an idea, or turn a first thought into a plan. I wanted it to feel easy to begin—and leave room for the thinking itself.

Your ideas should stay yours. You can save your maps as files, bring in a fresh perspective from an AI assistant, and decide what belongs. The tool should help you think, while you keep the pen.

This is a free personal project. I’m sharing it because a small, useful thing is worth putting into the world—and because seeing how other people use it is the best way to make it better.

Tell me what you’re thinking ↗

What’s the thought on your mind?

Start mapping