JSON Formatter

JSON Formatter is a lightweight tool designed for developers, API engineers, data scientists, QA teams, and technical writers who include JSON in documentation. Users paste or supply JSON payloads, API responses, configuration fragments, or log samples and require a deterministic, readable representation or a compact form suitable for storage, diffing, or transmission. It is widely used during API integration, data pipelines, data interchange, testing, and debugging to improve accuracy and reduce debugging cycles.
Core Logic & Features: The tool parses input strictly as JSON, detects syntax errors, and emits either a pretty-printed string or a minified version. Required features include robust parsing, correct handling of Unicode escapes, and precise error reporting with line and column information. Optional/advanced features include optional key sorting, adjustable indentation widths, a dedicated compact mode for logs, and deterministic output across repeated runs. All processing is client-side to preserve privacy, ensure low latency, and avoid server dependence.
Inputs & Outputs: Inputs include input_json (string), indent_size (integer 0-8, default 2), mode (string: pretty or minify), and sort_keys (boolean, optional). Outputs include output_json (string). On error, an error object with type, message, and location is produced. Validation ensures valid Unicode handling, correct escaping, and stable formatting across a variety of JSON structures (arrays, objects, nested values). The tool maintains the exact data payload while reformatting.
Algorithms & Error Handling/Localization: The tool uses a standard JSON parser (RFC 8259) to validate syntax; if valid, a serializer outputs the data with the chosen format. For pretty mode, indentation and newlines are applied; for minify, whitespace is removed while preserving data integrity. When sort_keys is true, object keys are sorted lexicographically before serialization. Error handling covers invalid syntax, oversized payloads, or non-JSON input with location details. Industry localization is JSON-UTF-8 based, with no locale-specific numeric formatting; assumptions include valid JSON input and exclusion of schema validation or data transformation beyond formatting; it runs entirely in-browser and does not rely on external data fetching.