JSON Formatter, Validator & Schema Checker
Beautify, minify, validate and explore JSON — with syntax highlighting, line numbers, tree view and JSON Schema validation.
About the JSON Formatter & Validator
Updated June 2026 · 100% client-side — your data never leaves your browser.
Bytewrench's JSON formatter beautifies, minifies, validates and explores JSON entirely in your browser. Paste raw JSON, upload a .json file, or load a sample, and the tool instantly pretty-prints it with syntax highlighting, line numbers and a collapsible tree view. Invalid JSON is flagged with the exact line and column so you can fix it fast.
Because everything runs client-side, your data never touches a server — making it safe for API responses, config files and payloads that contain sensitive information.
See also: JSON validator, JSON Schema validator, CSV to JSON converter
How to use it
- Paste your JSON into the input editor, upload a file, or click Sample.
- The formatted, syntax-highlighted result appears instantly on the right.
- Switch to Tree View to explore nested structures, or use Minify to compact it.
- Optionally paste a JSON Schema and click Validate to check your data against it.
Pretty-print with 2/4-space or tab indentation, or minify to the smallest valid output.
Explore deeply nested objects and arrays interactively, collapse or expand any node.
Validate against any Draft-07 JSON Schema with exact error paths and messages.
All parsing happens locally in your browser — your JSON is never uploaded.
Frequently asked questions
Why is my JSON invalid?
The most common causes are trailing commas, single quotes instead of double quotes, unquoted keys, comments, and missing or mismatched brackets. The formatter pinpoints the exact line and column of the first error so you can fix it quickly.
How do I fix an 'Unexpected token' error in JSON?
That error means the parser hit a character it didn't expect — often a stray comma, a missing comma between items, an unescaped quote inside a string, or a value that isn't wrapped in double quotes. Jump to the reported line and check the character just before the flagged position.
What is the difference between JSON and JSON5?
JSON is the strict standard: double-quoted keys and strings, no comments, no trailing commas. JSON5 is a relaxed superset that allows comments, single quotes, trailing commas and unquoted keys. This tool validates strict JSON, so JSON5-only features will be flagged as errors.
What is the difference between beautify and minify?
Beautify adds indentation and line breaks so JSON is easy to read. Minify removes all unnecessary whitespace to produce the smallest valid JSON, which is ideal for production payloads and API responses.
Is my JSON data sent to a server?
No. All formatting, validation and schema checking happen entirely in your browser, so it's safe for sensitive API responses and config files.