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JSON Repair

Paste broken JSON and get valid output in seconds—runs locally in your browser.

Try an example:
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Common Issues We Fix

Trailing commas
{"a": 1,}→{"a": 1}
Single quotes
{'a': 1}→{"a": 1}
Unquoted keys
{a: 1}→{"a": 1}
Missing commas
{"a": 1 "b": 2}→{"a": 1, "b": 2}
Comments
{"a": 1} // note→{"a": 1}
Truncated
{"a": [1, 2→{"a": [1, 2]}

What JSON repair does

CalcForge JSON Repair turns almost-valid JSON into parseable data. Instead of hunting line numbers in a validator, you get corrected output you can copy, download, or pipe into the next step of your workflow.

Good fits

  • Cleaning ChatGPT, Claude, or other model outputs that mix JavaScript habits with JSON syntax
  • Fixing config snippets copied from code comments or Stack Overflow answers
  • Recovering API payloads truncated mid-response or mangled during copy-paste
  • Preparing hand-edited `.json` files before validation, diffing, or conversion

Example transformation

// Input (invalid)
{name: 'Ada', skills: ['go', 'rust',],}

// Output (valid)
{"name":"Ada","skills":["go","rust"]}

Practical notes

  • Repair fixes structure, not business logic—always spot-check values after conversion.
  • Heavily corrupted files may need manual edits; pair with the error analyzer for precise line hints.
  • Your text never leaves the tab—ideal for internal configs and staging credentials.

Frequently asked questions

Will repair change my data values?

The tool normalizes syntax—quotes, commas, brackets—not semantic content. Numbers, strings, and nesting stay the same unless the original text was ambiguous.

Does it handle comments and trailing commas?

Yes. JSONC-style comments and trailing commas common in JavaScript object literals are stripped or corrected automatically.

Is my JSON uploaded to a server?

No. CalcForge runs entirely in your browser. Nothing is sent to our servers unless you explicitly share a link elsewhere.

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