Remove Null Fields from JSON Automatically Online

Paste JSON and every field set to null is removed as you type, at every level of nesting. You can also strip empty strings, whitespace-only strings, empty objects and arrays, and false or 0 values, and protect fields you want to keep, like deletedAt. The Removed tab lists the path and line of everything that was taken out, so you can check the result before you use it. Long numbers and IDs stay exact, and JSON Lines files are cleaned line by line. Everything runs in your browser.

How to remove null values from JSON

1. Paste your JSON into the left pane, or open a .json or .jsonl file.
2. The cleaned JSON appears on the right. If the JSON has an error, the exact line and column are shown.
3. Under Options, pick anything else to remove, and list any fields that should stay in Never remove.
4. Open the Removed tab to review what was taken out. Click a row to jump to it in your JSON.
5. Click Copy or Download.

What each option removes

Cleanup works from the inside out. With Empty objects turned on, an object that only held null fields is removed in the same pass, and so is its parent if that leaves the parent empty too.

Fields vs. array items

By default only object fields are removed, and arrays keep every item. In an array, position often carries meaning: [-122.67, 45.52] is a longitude and latitude, and a row of table cells lines up with its headers. Dropping a null from the middle shifts everything after it. If your arrays are plain lists, like tags or IDs, switch In arrays to Remove matching items.

Why remove null fields?

• Safer PATCH requests: with JSON Merge Patch (RFC 7396) and many REST APIs, sending null means "clear this field." Stripping nulls you didn't mean to send keeps you from erasing data.
• Smaller payloads: API responses and exports often carry dozens of empty fields per record. Removing them cuts size before storage or transfer.
• Fewer validation errors: JSON Schema, TypeScript types, and strict deserializers often reject null where a string or number is expected, but accept a missing optional field.
• Easier reading: without empty fields, the data that matters is much easier to scan.

Removing nulls with code

With jq, jq 'del(..|nulls)' file.json removes every null, including null items inside arrays. In JavaScript, JSON.stringify(data, (k, v) => v === null ? undefined : v) removes null fields from objects, but nulls inside arrays stay, because JSON.stringify writes undefined array items as null. In Python, a short recursive function works: rebuild each dict with {k: clean(v) for k, v in d.items() if v is not None} and each list with [clean(v) for v in items]. When you control the serializer, most libraries can skip nulls on output: NullValueHandling.Ignore in Json.NET, JsonIgnoreCondition.WhenWritingNull in System.Text.Json, and @JsonInclude(Include.NON_NULL) in Jackson.

Frequently asked questions