About this tool
JSON Formatter & Validator
Free JSON Formatter and Validator to format, validate and minify JSON online in your browser. Useful for APIs, configuration files and development.
About the JSON Formatter & Validator
JSON Formatter & Validator helps developers and technical users turn compact or difficult-to-read JSON into structured, indented data. It can also validate JSON syntax and produce a compact version for APIs, configuration files and data transfer.
How to use this tool
Paste valid JSON into the editor. Use Format to indent the data, Minify to remove unnecessary whitespace, or Validate to check syntax. If validation fails, Tervilo reports the parsing error returned by the browser JSON parser.
- Open the JSON Formatter & Validator page on Tervilo.
- Enter or paste the text you want to work with.
- Choose any options relevant to the task.
- Run the tool and review the result before copying or publishing it.
How the calculation or transformation works
JSON formatting does not change the underlying data model; it changes whitespace and indentation. Minification removes unnecessary formatting whitespace. The browser parser follows JSON syntax rules, so JavaScript objects containing comments, trailing commas or unquoted keys are not valid JSON until corrected.
Common uses
- API response inspection
- Configuration files
- Debugging request and response payloads
- Preparing readable JSON for documentation
- Minifying JSON before transfer
Privacy and browser-side processing
Tervilo's text tools are designed to process the text in your browser. For ordinary text-editing tasks this can reduce the need to send your content to an application server. Even with browser-side tools, review your organization's security requirements before pasting confidential, regulated or sensitive information into any website.
Related text tools
Explore the Text Tools category for related utilities such as the Word Counter, Character Counter, Case Converter and JSON Formatter.
Frequently asked questions
The FAQ section below covers common questions about this tool, its counting method and practical limitations.
Questions & Answers
Frequently Asked Questions
What makes JSON invalid?
Common problems include single quotes, trailing commas, comments, missing quotation marks and unclosed arrays or objects.
Can JSON Formatter minify JSON?
Yes. After valid JSON is parsed, Minify JSON removes formatting whitespace and returns a compact representation.