🩹 Developer toolFixes 15+ common errors

JSON Repair Tool

Paste broken JSON — from a log, an AI answer, JavaScript or Python — and get valid JSON back, with a list of every fix that was made.

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What was fixed
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    About the JSON Repair Tool

    The JSON Repair Tool turns almost-JSON into valid JSON. Data copied from JavaScript files, Python dictionaries, server logs or AI chat answers often has small errors: trailing commas, single quotes, keys without quotes, comments, True and None, or a missing closing bracket. A normal JSON validator just says “error”. This tool fixes them.

    It uses its own forgiving parser that reads the input the way a person would, then writes clean JSON in the indent you choose. The list on the right shows every fix, so you can check nothing important changed. Everything runs in your browser.

    How to use it

    1. 1Paste the broken JSON, open a file, or try the sample.
    2. 2The repaired, valid JSON appears on the right straight away.
    3. 3Read the list of fixes to see what was changed.
    4. 4Pick an indent or minify, then copy or download the result.

    What it can do

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    15+ repairs

    Trailing and missing commas, quotes, comments, literals, brackets, line breaks and more.

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    Python & JS input

    Reads True/False/None, undefined, NaN, hex numbers, JSONP and const x = {…}.

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    AI output ready

    Strips Markdown code fences and smart quotes from chatbot answers.

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    Shows every fix

    A clear list of changes, with a warning when the input needed guesswork.

    Frequently Asked Questions

    What kinds of errors can it fix?

    Trailing commas, missing commas, single quotes, backticks, unquoted keys, // and /* */ comments, Python True/False/None, undefined/NaN/Infinity, hex numbers, smart quotes, code fences, JSONP wrappers, line breaks inside strings and missing closing brackets.

    Will it change my data?

    It only changes syntax. Values that are not valid in JSON, such as undefined or NaN, become null, and the fix list tells you when that happened.

    How is this different from a JSON formatter?

    A formatter needs valid JSON and stops at the first error. The repair tool reads broken input and rebuilds valid JSON from it.

    Can it convert JSON5 or JavaScript objects to JSON?

    Yes. Unquoted keys, single-quoted strings, comments and trailing commas — the main JSON5 features — are all converted to standard JSON.

    Is my JSON uploaded?

    No. The repair runs entirely in your browser, so API keys or customer data in the JSON stay on your device.