Repair broken JSON — instantly, offline

Why valid-looking JSON still fails to parse

JSON is strict in ways that surprise people. A single character out of place and JSON.parse throws, usually with a cryptic "Unexpected token" that points at the wrong spot. The breakage almost always falls into a handful of buckets:

• Trailing commas. A comma after the last array item or object property is valid in JavaScript but illegal in JSON. braceful drops it.
• Single quotes & unquoted keys. Config files, logs and hand-edited fixtures often use 'value' or { key: 1 }. JSON requires double-quoted keys and strings; braceful rewrites them.
• Truncation. A payload copied from a terminal or cut off mid-write leaves an open string and unclosed braces. braceful closes the open structures so you can read the rest.
• Python & non-standard literals. None, True, False, NaN and Infinity are not JSON. braceful normalizes them to null, true, false and JSON-safe values.
• Comments. // and /* */ comments are common in JSONC and config files but break strict parsers. braceful strips them.

The repair is transparent: braceful shows the valid result and what it fixed, so you can confirm nothing meaningful was altered before you copy or download it. Because everything runs on-device, you can paste an API response full of tokens or a customer record without it being uploaded anywhere.

{
  name: "order-92",
  "items": [42, 17,]
  "paid": true,
  "note": "truncated at sav

{
  "name": "order-92",
  "items": [42, 17],
  "paid": true,
  "note": "truncated at sav"
}

Repairing a giant file too? Open large JSON files (~100MB) without freezing. If the broken JSON came out of an AI assistant, the fix JSON from ChatGPT & other LLMs guide covers the breakage those tools add (markdown fences, smart quotes, mid-response truncation). Once it parses, you can format & beautify it offline.