JSON Formatter & Validator
A JSON formatter takes raw, unreadable JSON — often minified into a single line by an API or copied from a log file — and turns it into clean, indented, human-readable text. MyJson’s formatter beautifies, validates and minifies JSON instantly in your browser, so you can spot structure and errors at a glance.
Because everything runs locally with no network calls, you can safely paste sensitive payloads such as API responses, configuration files or database records without any of it ever leaving your machine.
How to use the format json
- 1Paste your JSONCopy JSON from an API response, log, or file and paste it into the input panel. The editor auto-detects and highlights the syntax.
- 2Read the formatted outputValid JSON is instantly beautified with consistent indentation. If it is invalid, the exact line and reason for the error are shown so you can fix it.
- 3Adjust indentation or minifyChoose 2-space, 4-space, 8-space or tab indentation, or switch to Minify to compress JSON back into a single compact line.
- 4Copy or exploreCopy the result with one click, or switch to the interactive tree view to expand and collapse nested objects and arrays.
Features
- Pretty-print with 2, 4, 8-space or tab indentation
- Minify JSON to remove all whitespace
- Real-time validation with precise error locations
- Duplicate key detection with keep-first / keep-last fixes
- Collapsible tree view for large documents
When to use it
- Debugging an API response that arrived as one long minified line
- Reviewing a config file before committing it
- Validating JSON copied from logs or a browser network tab
- Reducing payload size by minifying before sending
Frequently asked questions
How do I format JSON online?
Paste your JSON into the input panel above. MyJson instantly validates it and prints a clean, indented version you can copy. No upload or signup is required.
Is my JSON data safe?
Yes. All formatting happens entirely in your browser using JavaScript. Your data is never uploaded to a server, so even confidential payloads stay private.
What does minifying JSON do?
Minifying removes every unnecessary space and line break, collapsing your JSON into a single compact line. This reduces file size for storage or network transfer.
Why is my JSON invalid?
Common causes are trailing commas, single quotes instead of double quotes, unquoted keys, or missing brackets. The validator points to the exact line so you can fix it quickly.
Related tools
Looking to learn more? Browse our JSON guides and tutorials.