Curv

Beautiful JSON tooling for developers.

Curv is a privacy-first, offline-ready JSON toolbox designed to help developers format, validate, inspect, compare and transform JSON with a clean and professional workflow.

Live Demo

https://lucamezzolla.github.io/curv/

Vision

Curv aims to become a complete JSON workspace for developers who need a fast, elegant and reliable tool for everyday API, backend, configuration and data inspection tasks.

Core Principles

• Privacy-first: JSON data stays local.
• Offline-ready: designed to work without a backend.
• Developer-focused: clean workflows, readable output and useful tooling.
• Elegant by default: professional interface and maintainable code.
• Extensible architecture: built to grow from formatter to full JSON studio.

Current Features

• Browser-based JSON formatter
• JSON minifier
• JSON validation workflow
• Deep JSON key sorting
• Remove null values from objects
• Semantic JSON diff
• Diff summary and path-level changes
• Diff filtering by change type
• JSON to YAML conversion
• JSON to CSV conversion
• JSON to Markdown table conversion
• JSON to query params conversion
• JSON to Java record conversion
• JSON to Java class conversion
• JSON to SQL CREATE TABLE conversion
• Copy left and right diff values
• Automatic JSON validation while typing
• Dedicated validation details panel
• Validation panel focus and flash feedback
• Improved JSON error details when available
• JSON file upload
• Output download
• Copy output to clipboard
• Clear workspace action
• Keyboard shortcuts
• Tab and Shift+Tab indentation
• Escape to blur the input editor
• Auto-format on paste for valid JSON
• Optional auto-format paste toggle
• Large input warnings
• Configurable indentation
• Input and output text statistics
• Basic JSON structure analysis
• Interactive JSON tree view
• Tree search
• Tree result counts
• Clear tree search
• Copy JSON path
• Copy JSON node value
• Selected tree node details
• Local-only processing
• Modular JavaScript architecture
• Responsive dark interface

Keyboard Shortcuts

Shortcut	Action
Ctrl + Enter / Cmd + Enter	Format JSON
Ctrl + Shift + M / Cmd + Shift + M	Minify JSON
Ctrl + Shift + V / Cmd + Shift + V	Validate JSON
Ctrl + Shift + S / Cmd + Shift + S	Sort keys
Ctrl + Shift + N / Cmd + Shift + N	Remove nulls
Ctrl + Shift + D / Cmd + Shift + D	Jump to JSON Diff
Ctrl + Shift + Y / Cmd + Shift + Y	Jump to converters
Ctrl + Shift + Q / Cmd + Shift + Q	Jump to Schema & Query
Ctrl + Shift + C / Cmd + Shift + C	Copy output
Ctrl + Backspace / Cmd + Backspace	Clear workspace
Tab	Indent selection
Shift + Tab	Unindent selection
Escape	Blur input editor

Planned Features

• Syntax highlighting
• Tree view for nested data
• JSON diff and comparison
• JSON Schema generation and validation
• JSONPath queries
• JSON to YAML, CSV, XML and Markdown conversion
• JSON to Java records, Java classes and SQL helpers
• Web and desktop distribution

Repository Structure

app/
  index.html
  assets/
    css/
      main.css
    js/
      main.js
      core/
        analyzer.js
        converter.js
        diffEngine.js
        editorCommands.js
        formatter.js
        queryTools.js
        schemaGenerator.js
        transformer.js
        validator.js
      ui/
        converterView.js
        diffView.js
        editor.js
        fileActions.js
        notifications.js
        preferences.js
        schemaQueryView.js
        theme.js
        treeView.js
        validationPanel.js

desktop/
  README.md

docs/
  privacy.md
  publishing.md
  roadmap.md

Project Status

Curv is currently in early development.

The current version provides a working browser-based formatter interface with formatting, minification, automatic validation, validation details, file upload, output download, copy, clear, keyboard shortcuts and basic text/structure statistics.

The next milestone focuses on syntax highlighting, tree view and stronger developer-focused inspection tools.

Running Locally

Curv is a static web application. It does not require a backend, but it should be served through a local HTTP server because the app uses JavaScript modules.

From the project root, open the app at:

http://localhost:8080/app/

Option 1: Python 3

python3 -m http.server 8080

Option 2: Node.js with npx serve

npx serve . -l 8080

Option 3: Node.js with npx http-server

npx http-server . -p 8080

Option 4: PHP built-in server

php -S localhost:8080

Option 5: Ruby

ruby -run -e httpd . -p 8080

Option 6: BusyBox

busybox httpd -f -p 8080

Option 7: VS Code / VSCodium Live Server

You can also use a Live Server extension from VS Code or VSCodium.

Open the project folder, start the local server from the editor, then open the generated local URL and navigate to:

/app/

Why a local server?

Opening app/index.html directly from the filesystem may not work correctly in some browsers because Curv uses ES modules:

<script type="module" src="./assets/js/main.js"></script>

Using a local HTTP server ensures the app behaves like it would in production.

Development Branch

This project currently uses development as the active working branch.

git checkout development

Versioning

The first foundation release is:

v0.1.0

The current development track is:

v0.8.0 — Publishing

License

To be defined.