How to clean JSON
Paste content into JSON input or load a file, then choose the changes to apply. JSON Cleaner trims string values, removes selected null or empty values, sorts object keys, and deduplicates array items recursively. Enable Strip JSONC comments & trailing commas when the source uses those additions, then compare Before with After.
- Paste JSON into JSON input, or use Drop a JSON or JSONC file here or browse files.
- Select Strip JSONC comments & trailing commas if the source contains comments or trailing commas.
- Choose Trim string values, Remove null values, or another option, then set Output indentation.
- Review Changes made, Before, and After.
- Select Copy Cleaned JSON or Export JSON.
What remove nulls from JSON changes
Trim string values and Remove null values are checked by default. The three empty-value options work independently, and each selected rule applies inside objects and arrays. A removal rule leaves the root JSON value in place.
{
"name": " Alice ",
"nickname": "",
"tags": ["b", "a", "a"],
"note": null
}The default checks trim the name and remove the null field:
{
"name": "Alice",
"nickname": "",
"tags": [
"b",
"a",
"a"
]
}How to sort JSON keys and deduplicate arrays
Sort object keys (recursively, A-Z) orders keys in every object, including nested objects. Deduplicate array items cleans each item first, then compares its JSON-stringified representation within that array. The first matching representation stays, later matches are removed, and the remaining order stays unchanged. Key order can affect whether two object items compare as duplicates.
How to clean JSONC comments and format output
Enable Strip JSONC comments & trailing commas to remove // line comments, /* block comments */, and commas immediately before } or ] before parsing. Comment markers inside quoted strings remain part of the string. The file picker accepts JSON, JSONC, and TXT, and reads files as UTF-8 text.
Output indentation can be 2 spaces, 4 spaces, Tab, or Compact (no whitespace). Before shows the parsed input with two-space indentation. After shows the cleaned serialization and can be edited. Copy Cleaned JSON and Export JSON use the current After text. For a file longer than 200,000 characters, the textarea preview is truncated while the full file is processed.
Where JSON cleaning comes up
A developer receives configuration JSON with padded names and null fields. The default checks trim the names and remove the null fields before the developer reviews the change summary.
A configuration file contains comments and trailing commas. Selecting Strip JSONC comments & trailing commas produces parseable JSON for the Before and After review.
A nested response contains repeated array items and inconsistent object order. Selecting Deduplicate array items and Sort object keys (recursively, A-Z) makes those changes visible before the cleaned text is copied or exported.
JSON Cleaner or JSONL Cleaner?
Use JSON Clean Tools when you are choosing among JSON cleanup pages. JSON Cleaner is for one parsed JSON value with recursive value and structure rules. Choose JSONL Cleaner when the input is JSON Lines (JSONL/NDJSON) and you need invalid or blank records removed, records deduplicated by full line or a chosen key, and a discard report.
JSON Cleaner does not repair broken syntax, flatten nested objects, convert formats, or compare two documents. A parse failure shows the browser's JSON.parse error message and keeps the workspace hidden until the input parses.
The JSON reading and cleanup code runs in browser JavaScript. The cleaner code does not send the JSON through fetch, XMLHttpRequest, sendBeacon, or a form post.
Frequently Asked Questions
How do I clean JSON with null and empty values?
Select Remove null values, Remove empty strings ( "" ), Remove empty arrays ( [] ), or Remove empty objects ( {} ) as needed. The selected rules remove matching values inside objects and arrays, while the root value remains.
Can I sort JSON keys recursively?
Yes, select Sort object keys (recursively, A-Z). It orders keys in every object, including nested objects, and the Changes made summary counts each object processed.
How does JSON Cleaner deduplicate array items?
It cleans array items first, then compares their JSON-stringified representations within each array. The first matching representation remains and later matches are removed.
Can I clean JSONC comments and trailing commas?
Yes, enable Strip JSONC comments & trailing commas before processing. It removes line comments, block comments, and trailing commas before JSON parsing, then shows parsed and reserialized JSON.
Does JSON Cleaner remove the root null or empty value?
No, removal rules leave the root JSON value in place. They can remove matching object properties, array items, and nested empty containers.