Remove Null Values from JSON Online — JSON Null Remover (Free) – DataMorph

Recursively remove all null values from JSON objects and arrays in one click. Free online JSON null remover — runs in your browser, nothing uploaded. Handles deeply nested JSON.

Remove Null Values from JSON Online

The JSON Null Remover recursively traverses your entire JSON tree and strips every key whose value is null from objects, and filters out null elements from arrays. The result is clean JSON ready for databases, APIs, or config files that don't accept null values. All processing happens locally in your browser — your JSON is never uploaded to any server.

Why Remove Null Values from JSON?

• Database compatibility — DynamoDB, Firestore, and many NoSQL databases reject or mishandle null values. Stripping nulls before writing avoids type errors and empty attribute warnings.
• Reduce payload size — REST APIs that return optional nullable fields often produce large responses. Removing nulls before caching or transmitting reduces bandwidth and storage costs significantly.
• Cleaner logs and configs — Configuration files and structured log entries are easier to read without null fields cluttering the output.
• GraphQL responses — GraphQL uses null for optional missing data. Frontend clients commonly strip nulls before rendering or storing the response.
• Data pipeline preprocessing — ETL processes often require null-free input. Removing nulls upstream prevents schema validation failures downstream.

How the Recursive Null Removal Algorithm Works

The tool uses a depth-first traversal of the JSON tree:

• Objects: Any key whose value is exactly null is deleted. Non-null object values are recursively processed.
• Arrays: Any element that is exactly null is filtered out. Non-null elements are recursively processed.
• Primitives: Numbers, strings, booleans, 0, false, and empty string "" are all preserved — only exact JSON null is removed.

Important: empty objects {} and empty arrays [] that result from null removal are retained in the output. Only null itself is removed — not falsy values.

Remove Null Values from JSON in Code

JavaScript (recursive):

function removeNulls(obj) {
  if (Array.isArray(obj)) return obj.filter(v => v !== null).map(removeNulls);
  if (typeof obj === 'object' && obj !== null) {
    return Object.fromEntries(
      Object.entries(obj).filter(([,v]) => v !== null).map(([k,v]) => [k, removeNulls(v)])
    );
  }
  return obj;
}

Python:

def remove_nulls(obj):
    if isinstance(obj, list):
        return [remove_nulls(v) for v in obj if v is not None]
    if isinstance(obj, dict):
        return {k: remove_nulls(v) for k, v in obj.items() if v is not None}
    return obj

Null vs Undefined vs Empty String in JSON

• null — Explicit absence of value. This tool removes it.
• undefined — Not valid JSON; serialized as null or omitted. If serialized as null, this tool removes it.
• "" (empty string) — Empty but present string value. This tool preserves it.
• 0 — Zero — valid numeric value. This tool preserves it.
• false — Boolean false — valid value. This tool preserves it.
• [] (empty array) — Empty array. This tool preserves it.
• {} (empty object) — Empty object. This tool preserves it.

Frequently Asked Questions

How do I remove null values from JSON online?

Paste your JSON into the input editor and click Process. The tool recursively removes all null keys from objects and null elements from arrays. Copy or download the cleaned JSON from the output panel. No account required, nothing uploaded.

Does this tool remove empty strings and zero values?

No. This tool strictly removes exact JSON null — not empty strings "", 0, false, [], or {}. Only explicit null values are stripped.

How do I remove null values from JSON in JavaScript?

Use: function removeNulls(obj) { if (Array.isArray(obj)) return obj.filter(v => v !== null).map(removeNulls); if (typeof obj === 'object' && obj !== null) return Object.fromEntries(Object.entries(obj).filter(([,v]) => v !== null).map(([k,v]) => [k, removeNulls(v)])); return obj; }

Does removing nulls from JSON also remove empty objects and arrays?

No. Empty {} and [] containers that result from null removal are preserved in the output. To also remove empty containers, run a second pass that filters them out after null removal.

Is my JSON data sent to a server?

No. All processing runs locally in your browser using JavaScript. Your JSON is never transmitted to any server — safe for sensitive API responses, credentials, or configuration files.