Affinity diagramming,
without the friction.

Splat is a lightweight, open-source tool for visually clustering ideas and insights. It runs entirely in your browser from a single HTML file — fast, local, and private, with optional AI assistance.

Screenshot of Splat affinity diagramming interface with AI assistance

Zero setup

Open a single HTML file and start clustering notes immediately. No installs, no accounts required.

Local & private

Your data stays in the browser by default. Use AI features only if and when you choose.

Visual sensemaking

Drag, group, color-code, and reorganize notes to surface themes and patterns in qualitative data.

AI-assisted workflows

Search notes semantically, highlight concepts, and perform bulk edits with natural language commands.

Designed for research

Ideal for UX research, brainstorming, interviews, and collaborative synthesis sessions.

Open source

Free and extensible under GPL-3.0. Inspect, modify, and contribute to the codebase.