JSON Formatter, Validator & Minifier
Pretty print, minify, validate, repair common JSON issues, inspect nested paths, and copy clean output for API responses, config files, logs, and test fixtures with browser-side processing.
Ready to use
Browser-side · no account · results stay on this page
Try a common JSON task
Shortcuts: Cmd/Ctrl+Enter formats JSON. Cmd/Ctrl+Shift+M minifies valid JSON.
Result ready
Object root, 6 object keys, 171 B before formatting.
Format or minify, then review the output before copying or downloading.
Valid JSON
Object root, 6 object keys, 171 B before formatting.
JSON tree and paths
Expand nodes to inspect nested values and copy JSON paths for debugging, docs, or JSON Path extraction.
$ Object(4)
$$.tool
"AscendLab JSON Formatter"
$.runsInBrowser
true
$.features Array(3)
$.features$.features[0]
"format"
$.features[1]
"minify"
$.features[2]
"validate"
$.limits Object(2)
$.limits$.limits.uploads
0
$.limits.backend
false
Next step
Keep going from this result
Use a related browser workflow to clean up, convert, or verify the current result.
Account workflows
Free browser tools stay free. Accounts, subscriptions, and credits are only for future PDF extraction and AI image/video translation workflow capacity.
A JSON formatter parses valid JSON and rewrites it with readable indentation.
Use minify when you need compact JSON, format when you need to inspect nested data, and tree view when you need to copy a JSON path.
Invalid input shows parser guidance, common repair hints, and line/column detail when the browser parser exposes it.
Use standard JSON
Wrap keys in double quotes and remove comments or trailing commas before validating, or use cleanup as a reviewable first pass.
Keep huge payloads local
For very large files, a local editor or command-line formatter may be faster than a browser page.
Formatted output uses two-space indentation. Minified output removes whitespace that is not part of string values.
Validation follows the browser JSON parser, so comments, trailing commas, and unquoted object keys are rejected. The repair helper can try a best-effort cleanup before you review the result.
The tree view walks the parsed object or array and exposes copyable paths for nested values.
This tool is useful for small and medium API payloads, webhook examples, config snippets, and logs that you want to inspect quickly.
For very large files, a local editor or command-line formatter may be more comfortable.
Example
Paste an API response, format it with indentation, expand the tree to copy $.data.users[0].id, then copy the cleaned result into a ticket, doc, or test fixture.
Assumption
Input should be valid JSON, not JavaScript object literal syntax.
Limitation
The browser must hold the full text in memory, so very large JSON files can feel slow. Cleanup is best-effort, standard parsing is not JSON5 support, and this is not a schema validator.
Pasting JavaScript objects
JSON requires double-quoted keys and strings. JavaScript object literals, comments, and trailing commas are not valid JSON.
Trusting cleanup blindly
The repair helper is for common comments, trailing commas, single quotes, and unquoted keys. Review the output before using it.
Formatting secrets in shared browsers
The tool runs locally, but copied payloads can still remain in clipboard history or browser memory on shared devices.
Using huge payloads casually
Large logs and exports can slow the browser. Use a local editor or command-line formatter for very large files.
API debugging
Pretty print response bodies, webhook payloads, and request examples.
Config cleanup
Validate app config snippets before pasting them into docs or test files.
Path inspection
Expand the tree and copy paths for nested fields before using a JSONPath extractor or writing docs.
Fixture prep
Minify or format JSON fixtures for tests, examples, and seed data.
Log inspection
Make nested JSON logs easier to scan when debugging local issues.
pretty print JSON
Use this when a compact payload needs readable indentation before review or sharing.
JSON minifier
Use minify when a valid fixture, config example, or embedded payload needs compact output.
API response formatter
Paste response bodies or webhook examples, validate them, then copy a readable version into a ticket or doc.
JSON repair trailing comma
Use cleanup when a pasted snippet has comments, trailing commas, single quotes, or unquoted keys.
copy JSON path
Use tree view when you need a path for a nested field before extraction, docs, tests, or debugging.
JSON syntax checker
Use the validator path when the only question is whether standard JSON parses before import or conversion.
How is JSON processed?
Formatting is designed to run in the browser based on the current public implementation. Avoid entering sensitive data unless you have reviewed the implementation.
Can I format JSON with comments?
No. Comments are not valid standard JSON, so the validator rejects them. The cleanup helper can try removing comments before you review the result.
What indentation does it use?
Formatted output uses two spaces, which is common for API examples and documentation.
Can I copy a path to a nested value?
Yes. Expand the JSON tree and copy the path for nested scalar values before using docs, tests, or the JSON Path Extractor.
Can I use it for API debugging?
Yes. It is a quick fit for pasted responses, request bodies, webhook payloads, and config snippets.
How is JSON processed?
Formatting is designed to run in the browser based on the current public implementation. Avoid entering sensitive data unless you have reviewed the implementation.
Can I format JSON with comments?
No. Comments are not valid standard JSON, so the validator rejects them. The cleanup helper can try removing comments before you review the result.
What indentation does it use?
Formatted output uses two spaces, which is common for API examples and documentation.
Can I copy a path to a nested value?
Yes. Expand the JSON tree and copy the path for nested scalar values before using docs, tests, or the JSON Path Extractor.
Can I use it for API debugging?
Yes. It is a quick fit for pasted responses, request bodies, webhook payloads, and config snippets.
Suggested workflow
JSON cleanup path
Move from conversion or pasted API data to formatted, inspected, and export-ready JSON.