JSONMaster is an all-in-one developer toolkit for visualizing, repairing, transforming, and monitoring JSON, YAML, XML, CSV, TOML, and PDF documents, built by solo developer rkmahale17 and available as a web application.
What is JSONMaster?
JSONMaster.com is a web-based toolkit that processes structured data formats—JSON, YAML, XML, CSV, TOML, and PDF—and outputs formatted, validated, converted, or visualized results. It runs entirely in the browser (no installation required) and is created by solo developer rkmahale17. Core functions include AI-powered formatting, syntax repair, interactive graph/tree/table visualization, real-time API monitoring, and schema generation.
Key Features
- AI-Powered Formatter — Automatically repairs broken JSON (fixes missing quotes, trailing commas, invalid structures) and formats data with smart indentation.
- Interactive Visualizer — Switch between Tree, Graph, and Table views for deep structural analysis of large JSON objects.
- Real-time API Monitor — Track uptime, performance, and accuracy of JSON APIs with instant notifications on failure.
- JSONPath Query Engine — Filter, extract, and transform complex JSON objects with real-time feedback and export results.
- Diff Checker — Advanced structural comparison and change detection between two data sets.
- Converters & Generators — Supports conversion between JSON, CSV, XML, YAML, TOML, and generation of random JSON data, JSON Schema, TypeScript interfaces, Python Pydantic models, Java POJOs, and Zod schemas.
- PDF Tools — Merge, split, unlock, secure, and convert PDFs to/from images (JPG, PNG) with local processing for security.
- Browser Extension — One-click access to format, repair, and visualize JSON/XML directly from the browser toolbar for Chrome and Edge.
Who is it for?
- Web Developers — Quickly format and validate API responses, debug JSON structures, and convert between data formats without leaving the browser.
- QA Engineers — Compare JSON payloads, monitor API health in real time, and generate test data with the random JSON generator.
- Data Analysts — Explore nested JSON using interactive visualizations (tree, graph, table) and extract insights with JSONPath queries.
- Solo Developers & Hobbyists — Access a free toolkit for learning JSON basics, repairing broken files, and generating schema definitions.
What can you do with JSONMaster?
- Debug API Responses: Paste a JSON response into the formatter, auto-repair syntax errors, and view the structure in tree mode to find missing keys.
- Monitor Production APIs: Set up real-time monitoring for uptime and performance metrics; get notified when an endpoint fails.
- Convert Between Formats: Transform CSV to JSON for integration, or convert JSON to YAML for configuration files.
- Generate Type Definitions: Take a JSON sample and instantly generate TypeScript interfaces or Python Pydantic models to enforce schema in code.
- Process PDFs Locally: Merge, split, or unlock PDF files directly in the browser without uploading to any server.
How does JSONMaster work?
Most tools work by pasting input data into a browser-based editor, selecting an operation (format, validate, convert, visualize), and receiving instant results. The API Monitor requires registering an endpoint URL; the system then pings it periodically and displays health metrics on a dashboard.
Pricing
JSONMaster is freemium. Basic tools like formatting, validation, and conversion are free. Advanced features such as the visualizer, monitor, and cloud save may require a paid plan (specific tier names are not listed on the homepage).
Alternatives
- JSONLint — a simpler validator focused on JSON syntax checking.
- JSON Generator — for generating random JSON data.
- Postman — provides API monitoring and testing but is a heavier desktop application.
FAQ
Is JSONMaster free?
Yes, core tools like formatting, validation, and most converters are free. Some advanced features (visualizer with cloud save, API monitoring) are part of a freemium model.
What formats does JSONMaster support?
It supports JSON, YAML, XML, CSV, TOML, and PDF. You can convert between these formats and also generate schemas and type definitions.
Does JSONMaster store my data?
Most operations happen client-side in the browser. Cloud save is available for visualizer states if you choose to use it. PDF tools process files locally and do not upload to servers.
Who created JSONMaster?
It was built by solo developer rkmahale17, as stated on the GitHub profile.
Can I use JSONMaster offline?
No, it requires an internet connection because it is a web application. However, the browser extension provides quick access while online.
