Format or minify strict JSON in your browser, then copy the result. Paste an object, array, string, number, boolean, or null. The formatter checks JSON syntax and changes whitespace outside strings; it does not validate an application schema or upload your input.
Format JSON
Strict JSON only: comments and trailing commas are not allowed.
Choose an action to check and format the input.
What does formatting change?
JSON allows insignificant whitespace around structural characters. This tool checks the input with the browser's JSON parser, then adjusts whitespace outside quoted strings. It preserves string escapes and number text as entered. Choose Format to add line breaks and indentation, or Minify to remove whitespace outside strings.
A successful parse only checks JSON syntax. It does not confirm that keys, value types, or other fields match a particular API, MCP client, or application schema. JSON comments and trailing commas are not part of strict JSON syntax; remove them before formatting.
Does this send or save pasted JSON?
No. Parsing and formatting run in the current browser page. This page does not make a request containing your input or save it to browser storage. Avoid pasting live credentials into any website form.
Frequently asked questions
Can it format a JSON array or a primitive value?
Yes. The input can be any single valid JSON value, including an object, array, string, number, boolean, or null.
Why does a JSON comment cause an error?
JSON syntax does not include comments. Remove comment text and try again; this tool does not convert JSON-like configuration formats into JSON.
Does valid JSON mean my configuration will work?
No. Syntax validity does not check required fields, supported options, credentials, or whether a program accepts that JSON for its own schema.
What demand evidence supports this tool?
seodata.dev reports 18,100 average monthly US searches for “json formatter online” from the Google Ads API, with its keyword page updated May 11, 2026 and observed November 4, 2026. That is a third-party keyword estimate, not this site's traffic or a forecast.
Sources · checked November 4, 2026
Related: compare two JSON responses by path, or use the MCP configuration checker for limited target-specific structure checks.
Methodology and limitations
The page validates a single JSON value with the browser's built-in JSON parser, then adjusts whitespace outside quoted strings without reserializing strings or numbers. It offers pretty output at a user-selected indentation width or minified output. It does not check an application schema, send input to a service, or save input in browser storage. seodata.dev reports 18,100 average monthly US searches for “json formatter online” from Google Ads API data; the page was updated May 11, 2026 and observed November 4, 2026. This third-party keyword estimate is not this site's traffic or a forecast.
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