Editable source
Read-only formatted JSON
JSON Guide
Use this browser-based JSON formatter to make JSON easier to read, validate structure, inspect nested data, and understand common issues before using JSON in APIs, config files, logs, or developer workflows.
Formatting parses JSON and writes it back with indentation and line breaks. It does not change valid data values, but it can normalize object key order as parsed by the browser and remove duplicate keys because the last value wins.
Valid JSON needs double-quoted keys and strings, matching braces and brackets, no trailing commas, and supported values such as strings, numbers, booleans, null, objects, and arrays.
Duplicate keys are risky because parsers usually keep only the last value. This tool warns about repeated keys in Inspector so you can review the source before formatting input removes duplicates.
Formatted JSON is easier to read and debug. Minified JSON removes extra whitespace to make the output smaller for transport, embedding, or compact storage.
The tree view helps navigate nested objects and arrays. Inspector summarizes validation, duplicate-key warnings, object counts, array counts, depth, total keys, and visible output size.
JSON processing runs locally in your browser. The formatter, minifier, validator, tree view, and duplicate-key scanner do not send your JSON content to a server.