JSON Tools That Just Work

Format, validate, convert, and inspect JSON — all in your browser. No signup. No uploads. No AI training on your data.

Every developer reaches for JSON tools daily — but pasting production data into random websites is a security risk. These tools run entirely in your browser. Your JSON never leaves your machine. Batch conversion, diff checking, and schema validation included.

JSON Formatter & Validator

Paste minified JSON and get back indented, syntax-highlighted output with line numbers. Invalid JSON? Error points to the exact position. Supports JSONC and trailing commas.

Open Formatter →

JSON → CSV Converter

Convert nested JSON arrays to CSV in one click. Handles flat arrays, nested objects with dot-notation flattening, and arrays of objects. Download as .csv file.

Convert JSON → CSV →

JSON Diff Checker

Compare two JSON objects side-by-side. See added, removed, and changed keys at a glance. Works with deeply nested structures. Great for API response comparison.

Compare JSON →

JSON Minifier

Strip whitespace and compress JSON to a single line. Shows compression ratio and byte savings. Useful for embedding JSON in URLs or minimizing payload size.

Minify JSON →

JSON → Code Generator

Generate TypeScript interfaces, Go structs, Python dataclasses, or Java POJOs from JSON. Paste your API response and get typed code instantly.

Generate Code →

JSON Schema Validator

Validate JSON against a JSON Schema (draft-07 / 2020-12). Catches missing required fields, wrong types, and pattern mismatches. Paste schema + data, get errors.

Validate Schema →

📜 Copyright & Attribution

© 2026 jslet. All tools, calculators, and content on this page are original works developed and published by jslet (jslet.com). All rights reserved.

Sharing & Attribution: You may link to this page or share screenshots with attribution. Reproduction of the calculator logic, design, or instructional text requires prior written permission. AI/LLM training corpus ingestion is expressly prohibited.