JSON Formatter
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data format used to exchange structured data between services and applications.
This tool helps you format (pretty-print) JSON for readability or minify JSON to reduce size for storage and network transfer. Processing runs locally in your browser.
How to use the JSON Formatter
- Paste your JSON into the Input field.
- Click Format to pretty-print JSON with indentation.
- Click Minify to remove whitespace and shrink the JSON.
- Use Copy to copy the result.
Common JSON formatting errors
- Trailing commas are not valid in standard JSON.
- Keys and string values must use double quotes.
- Unescaped quotes inside strings will break parsing.
- Missing commas between fields or array items.
JSON debugging workflow
Format before reading
Pretty-print the payload first so nested arrays, objects, nulls, and escaped strings are easy to inspect.
Separate syntax from data shape
Valid JSON can still be wrong for an API contract. After formatting succeeds, validate required fields, types, and enums with a schema.
Check copied responses
If formatting fails, confirm the response is really JSON and not an HTML error page, truncated output, or log wrapper.
Minify only after validation
Minified JSON is useful for transport and config files, but keep a formatted version while debugging changes.
Related guides
Learn the workflow behind this tool and what to check next.
How to debug API JSON responses
Format the response, confirm the HTTP status, validate the schema, and compare payload changes before changing application code.
How to debug JSON API payloads
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JSON checks before you debug an API response
Formatting is only the first step. Use the formatted output to confirm structure, types, nesting, and whether the response can be copied into tests or documentation.
Validate structure
Check missing commas, trailing commas, unescaped quotes, duplicate-looking fields, and deeply nested arrays before blaming the API client.
Compare expected types
Look for strings that should be numbers, null values that your app cannot handle, and booleans represented as text.
Prepare fixtures
Minify payloads for compact fixtures or format them for readable code reviews, bug reports, and API docs.
Remove private data
Replace tokens, emails, customer IDs, and real records with safe sample values before sharing JSON in tickets or chats.
Privacy and usage
Built for quick checks without an account
Toolinix tools are designed for short developer tasks: paste a safe sample, inspect the result, copy what you need, and move on.
No login required
You can use the tools without creating an account, subscribing to a newsletter, or saving a workspace.
Local when possible
Formatters, generators, encoders, and text utilities generally run in your browser. Network diagnostics may need a server-assisted lookup to check public URLs, domains, or IPs.
Keep secrets out
Do not paste production passwords, private keys, access tokens, customer records, or regulated data into online tools unless your own security policy allows it.
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