Overview
massCode is a free and open source developer workspace for code snippets, markdown notes, calculations, and quick developer utilities. Instead of scattering everyday work across an editor, a notes app, a calculator, and a handful of websites, you keep it in four focused Spaces inside one local-first desktop app.
Switch between Spaces using the rail on the left side of the app.
Code
Use Code to build a reusable snippet library across projects and languages. The three-column layout keeps organization, search, and editing in one place: Library on the left, snippet list in the middle, editor on the right.
Notes
Use Notes for longer markdown documents that do not fit well into snippets: project notes, drafts, technical docs, meeting notes, and personal knowledge bases. It uses the same three-column layout as Code and adds live preview, mindmaps, and fullscreen presentation mode.
Math
Math is a calculator-style notebook for quick development math without leaving massCode. Use it for currency conversion, unit conversion, date math, finance, and natural-language calculations with instant results on every line.
Tools
Tools covers the small one-off tasks that usually send you to a browser tab: encoders, decoders, generators, hash utilities, and text converters. Categories are listed on the left, and the active tool opens on the right.
General Settings
Sidebar Toggle
Hide or show the Library sidebar in Code and Notes:
- Select "View" > "Toggle Sidebar" from the menu bar or press Alt+Cmd+B on macOS or Alt+Ctrl+B on Windows or Linux.
Font Size
Adjust the editor font size in Code and Notes:
- Cmd+= / Ctrl+= increase
- Cmd+- / Ctrl+- decrease
- Cmd+0 / Ctrl+0 reset to default
Preferences
Open the main preferences window:
- Press Cmd+, on macOS or Ctrl+, on Windows or Linux.
Compact List Mode
Code, Notes, and Math support a compact list mode that reduces item height, so you can see more folders, notes, snippets, or sheets at once.