JSON Formatter / Validator
How to Use the JSON Formatter / Validator
JSON (JavaScript Object Notation) is the standard data interchange format for APIs, configuration files, and structured logs. Raw JSON from network responses often arrives minified — one long unreadable line. A JSON formatter parses the input, validates syntax, and re-output with consistent indentation so you can read nested objects and arrays at a glance.
Validation catches syntax errors before they break production: missing commas, trailing commas in strict parsers, unquoted keys, single quotes instead of double quotes, and unescaped control characters. Error messages pinpoint the line and column where parsing failed, saving hours of squinting at minified API responses.
Minify mode removes whitespace for compact transmission — the opposite of pretty-print. Use minified JSON in API requests where byte size matters. Sort object keys alphabetically for stable diffs when comparing two JSON documents in the text compare tool.
Common fixes: wrap bare strings in quotes, replace undefined with null, escape backslashes and newlines inside string values. For URL-embedded JSON, decode with the URL encoder first; for Base64-wrapped payloads, decode with Base64 before formatting here.
Whether you are debugging a REST API response, editing a package.json snippet, or validating webhook payloads, JSON formatting turns opaque strings into readable structured data with instant syntax verification.
Common use cases
API debugging
Pretty-print API responses to inspect nested fields during integration development.
Config editing
Format and validate application config files, CI/CD manifests, and package.json snippets.
Log analysis
Expand structured JSON log entries for readable field inspection during incident response.
Webhook testing
Validate incoming webhook payloads and identify syntax errors before processing.
Documentation
Format JSON examples with consistent indentation for technical docs and tutorials.
Frequently asked questions
Common causes: trailing commas, single-quoted strings, unquoted keys, missing commas between elements, or unescaped special characters.
Format adds indentation and line breaks for readability. Minify removes all unnecessary whitespace for compact output.
Standard JSON does not allow comments. Remove // and /* */ comments before validating strict JSON.