Tools lab · JSON
Free JSON Formatter
Validate, pretty-print, and minify JSON for APIs and config files.
Formatter & validator
Paste JSON, validate it, and get pretty and minified versions side by side.
Input JSON
Paste payloads from clients, logs, or config files.
Errors show below with the message returned by the parser.
Formatted JSON
Minified JSON
How this JSON formatter works
Step 1
Paste JSON
Drop in JSON from logs, Postman, cURL, or your editor.
Step 2
Validate & format
Run validation and pretty‑print with a single click.
Step 3
Copy and reuse
Copy the formatted or minified output into clients or configs.
Frequently asked questions
What does this JSON formatter do?
The tool takes raw JSON, checks whether it is valid, and then produces a human‑readable pretty version and a compact minified version side by side.
This makes it easier to debug API responses, configuration files, and logs without manually adjusting indentation or worrying about syntax.
How is JSON validity checked?
When you click “Format & validate”, the input is parsed using a JSON parser; if the parser succeeds, the JSON is considered valid and can be reformatted.
If there is a problem, the parser returns an error message and the tool shows that message so you can see roughly where the issue occurred.
What is the difference between formatted and minified JSON?
Formatted JSON includes line breaks and indentation so nested objects and arrays are easy to scan visually in an editor or code review.
Minified JSON removes unnecessary whitespace so the payload is as small as possible, which is useful for production configs, embeds, or network transfer.
Why am I getting an “Invalid JSON” error?
Common causes include missing commas, trailing commas, unquoted keys, or using single quotes instead of double quotes around strings.
Check the error message for a line or character position, fix the highlighted area, and click “Format & validate” again to confirm the structure is now valid.
Can I use comments in my JSON?
Strict JSON does not support comments, so lines starting with // or blocks like /* */ will cause validation errors in this tool.
If you need comments, consider using a separate configuration format such as JSON5, YAML, or environment variables where comments are allowed.
Is this safe to use with sensitive payloads?
The front‑end is designed so you can paste JSON directly in your browser; for highly sensitive data, use the tool over HTTPS and avoid sharing screenshots or logs that include secrets.
For production secrets such as API keys or tokens, prefer masking values before sharing JSON outputs with team members or external tools.
What are typical use cases for this formatter?
Developers commonly use it to inspect API responses, clean up request bodies, review webhook payloads, and quickly sanity‑check configuration files.
It is also helpful when debugging integrations from tools like Postman, Insomnia, or front‑end apps that log JSON directly to the console.