Repair broken JSON

Fix invalid JSON: comments, quotes and commas

The longest worked example is a staging config copied straight out of a .js file, with comments, unquoted keys, single quotes, an undefined and two trailing commas — five different problems in eleven lines, which is what real pasted config looks like. That guide works it through from the paste to the status line, then covers what the repair deliberately leaves alone, and why your indentation and key order survive it.

JSON from an AI model

Sure! Here's the config you asked for:

```json
{
  "service": "orders-api",
  "retries": 3
}
```

Let me know if you want it as YAML.

Removed a Markdown code fence
Removed text around the code block

{
  "service": "orders-api",
  "retries": 3
}

A model asked for JSON tends to answer like a person: a line of introduction, a Markdown code fence marked json, and an offer to do something else afterwards. Repair recognises the fence, drops the chat around it and keeps what was inside, and it says both things separately — the fence, then the text around the block — so you can see that nothing from inside the fence was touched.

It also copes with the answer that ran out of room. A reply that stops at {"items": [1, 2, 3 comes back as a complete object with its array and its brace closed, reported as Closed unterminated brackets. What it cannot do is invent the items that never arrived, so check the tail of anything it had to finish for you.

Two fenced JSON blocks in one answer are refused rather than guessed between, with the count in the message: This has 2 JSON code blocks — delete all but the one you want, then Repair. A block marked as another language is refused by name — That code block is marked yaml, not JSON. — and for that one the Convert page is the right tool.

Values from another language

{
  'service': 'orders-api',
  'active': True,
  'deleted': False,
  'owner': None,
  'retries': undefined,
  'ratio': NaN
}

Converted single-quoted strings (7)
Converted Python literals (3)
Replaced NaN and Infinity with null
Replaced undefined with null

{
  "service": "orders-api",
  "active": true,
  "deleted": false,
  "owner": null,
  "retries": null,
  "ratio": null
}

A dictionary printed by Python and an object pasted out of JavaScript bring their own spellings for things JSON writes differently. True, False and None become true, false and null, counted together as Python literals. Single quotes become double ones, keys and values alike, which is why the count here is seven rather than six.

undefined and NaN are the two that cannot be translated, only replaced. JSON has no word for an absent value beyond null, and its number grammar has no room for a not-a-number or an infinity, so both are written as null and each is reported on its own line. Nothing is invented in their place: inventing a number would be the one change you could not spot later. If a field mattering to you comes back null, that line of the list is where to look.

Log lines and NDJSON

{"level": "info", "msg": "started", "ms": 12}
{"level": "warn", "msg": "slow query", "ms": 940}
{"level": "error", "msg": "timeout", "ms": 3000}

Wrapped multiple top-level values in an array

[{"level": "info", "msg": "started", "ms": 12},
{"level": "warn", "msg": "slow query", "ms": 940},
{"level": "error", "msg": "timeout", "ms": 3000}]

A log file, a JSON Lines export and the output of a streaming API all look the same: one complete object per line, no commas between them and no brackets around the lot. Each line is valid on its own, which is what makes the format useful, and the whole file is not a JSON document at all — a document has exactly one top-level value.

Repair wraps the run of values in an array and says so, and the result is something the rest of the editor can work with: the tree shows one row per record, the table gives you a column per field, and a search or a JSONPath query runs over the lot. The line breaks are kept where they were, so a thousand-line log stays a thousand readable lines rather than becoming one very long one. Press Format afterwards if you would rather it were indented.

When Repair refuses

The upstream service replied with 502 and the body below.
Retry after 30 seconds.
{ "error": "bad gateway", "retryAfter": 30 }
Nothing else was logged.

Nothing here could be repaired automatically.

There is an object in that text, and Repair leaves it alone. The status bar says Nothing here could be repaired automatically. and the document is untouched.

This is the deliberate limit, not a gap. Pulling a {…} out of arbitrary prose means guessing where the document starts and stops, and the thing that most often arrives wrapped in prose is an HTML error page with a fragment of JSON somewhere inside it. Guessing there would hand you a document that parses and is not the one the server meant, which is worse than a refusal because you would have no reason to check it. A code fence is different: somebody drew that boundary on purpose, so the fenced case above is repaired and this one is not.

A separate message covers the other kind of failure. When the fixes do apply but the result still will not parse, the document is kept and the bar reads Could not repair this automatically — the remaining errors are marked in the editor. The underlines are then the place to look, and fixing the first by hand usually unblocks the rest.

Format, Minify and Sort keys

{ "name": "orders-api",
    "retries": 3,
  "active": true, "tags": ["eu","prod"] }

Format
{
  "name": "orders-api",
  "retries": 3,
  "active": true,
  "tags": [
    "eu",
    "prod"
  ]
}

Minify
{"name":"orders-api","retries":3,"active":true,"tags":["eu","prod"]}

Sort keys
{
  "active": true,
  "name": "orders-api",
  "retries": 3,
  "tags": [
    "eu",
    "prod"
  ]
}

Format, with Indent set to 4
{
    "name": "orders-api",
    "retries": 3,
    "active": true,
    "tags": [
        "eu",
        "prod"
    ]
}

Once a document parses, three more commands rewrite it without changing what it means. They sit in each pane’s toolbar under Transform. Format prints it with one value a line and the nesting indented; Minify removes every space and line break, which is what you want before pasting into an environment variable; Sort keys puts every object’s keys in alphabetical order while leaving array order alone, because an array’s order is data and an object’s is not.

Format and Sort keys both write the indent set in Settings, which offers two, three or four spaces or a tab, and they read it at the moment you press — so the fourth run above differs from the first only in that setting. Sorting the keys of two files before comparing them is the quickest way to stop a diff reporting a reordering as a change.