massCodeYour developer workspace

Build a reusable code library across projects and languages. Organize snippets with folders, tags, and fragments, then edit them with CodeMirror , format them with Prettier , preview HTML & CSS in real time, inspect JSON visually, and export polished screenshots when you need to share code.

Keep technical notes, task notes, docs, and drafts next to your snippets. Write in Markdown with live preview, add status, priority, and due dates to task notes, organize with folders and tags, and use Mermaid diagrams, mindmaps, or fullscreen presentation mode when you need more structure. Plan linked notes, snippets, and requests while writing, then create them when ready. Use the Note inspector to reorder sections, inspect links, and find callouts.

Build and test HTTP, GraphQL, and WebSocket APIs. Organize collections with shared auth and variables, switch environments, and keep secrets locally. Check responses with assertions and JavaScript tests, run request sequences, and debug traffic in Console. Import collections from OpenAPI, Postman, and Bruno. Explore the HTTP client .

Do the quick calculations that usually break your flow. Natural-language math handles inputs like time in Tokyo, density of honey, and $500 invested $1,500 returned for currencies, time zones, unit conversion, finance, and date math.

Sketch diagrams, wireframes, and whiteboard ideas on an Excalidraw -powered canvas. Keep a searchable list of drawings beside your snippets and notes, recenter with fit-to-content, export them as images, and embed drawings directly in your Markdown notes.

Handle the small developer tasks that usually send you to a browser tab. Convert, encode, hash, and generate data right inside massCode with tools for JSON, Base64, URLs, colors, passwords, UUIDs, and more.

Bring existing libraries into your local vault. Import snippets from VS Code, Raycast, SnippetsLab, and public GitHub Gists, or import Obsidian markdown folders into Notes with a preview before writing.

Bring your snippet library into the tools you already use. VS Code Extension for searching and inserting snippets, and Raycast Extension for quick access from anywhere.

Keep your data on your machine and in your control. Notes and snippets are stored as plain Markdown files, so syncing with iCloud, Dropbox, or Git stays simple and portable.

Use massCode in the language you are most comfortable with. The app is available in 15 languages, including English, Deutsch, Español, Français, Русский, 日本語, and 中文.