A free, open-source code snippet manager to create, organize, and instantly access your personal snippet library.
Built with Electron, Vue & Codemirror.
Inspired by applications like SnippetsLab and Quiver.
Latest Release | Documentation | Change Log
SPONSORS
Support
massCode is an open-source project and completely free to use.
Maintaining and adding new features requires significant time and effort. If you find massCode useful, consider supporting its development. Your contribution helps keep the project alive and moving forward.
You can support massCode through the following channels:
Features
Organization
Organize your snippets with multi-level folders and tags. Each snippet can contain multiple fragments (tabs), giving you fine-grained control over structure and grouping.
Editor
Built on CodeMirror with .tmLanguage grammars for syntax highlighting.
- Supports over 600 grammars, with 160+ available out of the box.
- Integrated Prettier for clean, consistent code formatting.
Real-time HTML & CSS Preview
Write and instantly preview HTML and CSS snippets. Perfect for prototyping, testing ideas, or quick visual checks.
Markdown
Full Markdown support with syntax highlighting, tables, lists, and more.
- Integrated Mermaid for dynamic diagrams and charts.
Presentation Mode
Turn a sequence of snippets into a presentation. Useful for classrooms, team meetings, conference talks, or simply walking through your own notes.
Mindmap
Generate mind maps from Markdown. Fast, intuitive, and ideal for structuring and visualizing ideas.
JSON Visualizer
Visualize and explore your JSON data with an interactive graph view. Perfect for quickly inspecting complex responses, APIs, or configuration files.
Beautiful Screenshots
Export snippets as polished images with customizable themes and backgrounds.
Developer Tools
Handy built-in utilities for everyday dev tasks:
- Text Tools: Case Converter, Slug Generator, URL Parser
- Crypto & Security: Hash/HMAC, Password Generator, UUID
- Encoders/Decoders: URL, Base64, JSON ⇄ TOML/XML/YAML, Text ⇄ ASCII/Binary/Unicode, Color Converter
Integrations
Extend your workflow with:
- VS Code Extension: zen mode snippet search, instant insertion, and save selected code as snippets.
- Raycast Extension: quick snippet access directly from Raycast.
Overview
massCode was created as a personal learning project and evolved into an open-source tool. The goal: combine the best features of snippet managers (free and paid) into one flexible, developer-friendly application.
Build Locally
Prerequisites
- Node.js (>=20.16.0)
- pnpm (>= 9.0.0)
Install Dependencies
Build
To build for current platform:
To build for a specific platform:
pnpm build:mac # macOS pnpm build:win # Windows pnpm build:linux # Linux
Development
To run in development mode:
This will start the application with hot reloading.
Troubleshooting
macOS
If you encounter the error message "massCode" is damaged and can't be opened. You should move it to the Trash while installing software on macOS, it may be due to security settings restrictions in macOS.
Option 1: System Settings (macOS 13+)
- Open System Settings → Privacy & Security
- Scroll down to find "massCode" in the list of blocked applications
- Click Allow Anyway or Open Anyway
- You may need to enter your administrator password
Option 2: Terminal command
sudo xattr -r -d com.apple.quarantine /Applications/massCode.app
Follow
- News and updates on X.
- Discussions.
License
Copyright (c) 2019-present, Anton Reshetov.

