JSON Tools Online
A complete suite of free JSON utilities for developers — format, validate, convert, query, and generate types from JSON. Everything runs in your browser with no data uploaded.
Format compact JSON into readable indented output. Validate syntax and detect errors with line numbers. Minify for production.
Convert between JSON and YAML instantly. Paste either format and get the other — useful for Kubernetes, Docker, and CI/CD configs.
Convert JSON arrays to CSV with auto-detected headers. Download the result or copy to clipboard. Handles nested objects.
Generate TypeScript interfaces and types from a JSON sample. Handles nested objects, arrays, and optional fields automatically.
Test JSONPath expressions against your JSON data. See matching nodes highlighted in real time.
Validate a JSON document against a JSON Schema (draft-07/2019-09/2020-12). See all validation errors with paths.
Convert a JSON array to JSON Lines (newline-delimited JSON). Used by BigQuery, LLM fine-tuning datasets, and log pipelines.
Why use online JSON tools?
JSON (JavaScript Object Notation) is the dominant data format for APIs, configuration files, and data exchange. Developers work with JSON dozens of times a day — debugging API responses, editing config files, writing tests, and converting data between systems.
These tools eliminate the need to write throwaway scripts. Need to check if an API response is valid JSON? Paste it into the formatter. Need TypeScript types for a new API? Paste the response into the JSON to TypeScript converter. All tools process data locally in your browser — nothing is uploaded.