JSON/XML Formatter Online Free

Provides on-demand formatting and validation of JSON and XML text. The tool targets developers, QA engineers, API teams, and data engineers who receive compact payloads, logs, or sample data and need readable, diff-friendly output. By preserving data semantics and applying consistent indentation, it enables easier review, documentation, and integration testing. It supports both single-shot formatting and batch-like workflows via an API, and is suitable for inclusion in CI pipelines to ensure standardized payload presentation.
Core logic and features: Domain capabilities include syntax-aware formatting for JSON and XML, optional validation, and detailed error reporting. Required features: parse input according to RFC 8259 for JSON or XML 1.0, detect syntax errors with position metadata, and produce pretty-printed output that preserves data semantics. Outputs include formatted_text, is_valid, and error_details. Optional/advanced features: indentation configuration (2 or 4 spaces), compact/minified output, preservation of JSON key order, deterministic XML attribute layout, namespace handling options, and the ability to produce a side-by-side transformer output for diff-friendly comparisons. The tool avoids altering content beyond formatting.
Inputs & Outputs: Inputs include input_text (string, required), format (JSON or XML, required), indent (integer, 2 or 4, optional), preserve_order (boolean, optional). Outputs include formatted_text (string), is_valid (boolean), and errors (string, optional). The tool returns outputs that reflect the original data types and ordering when possible and includes error_details to guide correction. It supports both minified and already pretty-printed input and outputs ready-to-use text for docs, tests, and diffs.