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JSON Cleaner

SmartFreePrivateRecursive

Strip noise from real payloads: nulls, empty strings, hollow objects and arrays — with a clear impact summary so you know exactly what changed.

Input JSON
Cleaned JSON

Remove empty fields instantly

Ctrl+Enter Clean

JSON Cleaner: Remove Nulls and Empty Fields from JSON

Paste any JSON and clean it up in one click. This JSON cleaner strips null values, empty strings, empty objects, and empty arrays: recursively, so nothing slips through nested structures. Use it for a quick JSON cleanup before storing, shipping, or sharing a payload. After each run you see how many fields were removed, optional removed paths for developers, and approximate size savings. Everything runs in your browser, nothing is uploaded.

Why Clean JSON?

Reduce Payload Size
Removing nulls and empties shrinks payloads (often 20–50%). Inspect the delta before/after with JSON Diff when tuning API contracts.
Improve API Performance
Smaller JSON serializes faster over the wire. Share trimmed samples with partners through JSON → CSV when they live in spreadsheets.
Cleaner Code
APIs without noisy nulls are easier to consume. After cleaning, format consistently with the JSON Formatter and document fields using JSON Schema.

How to Use

  1. Paste your JSON into the input panel
  2. Choose cleanup rules (nulls, empty strings, empty objects, arrays): on mobile, open More for toggles
  3. Click Clean or press Ctrl+Enter
  4. Review the impact summary, then copy or download the cleaned JSON

Example

Input
{
  "name": "Alice",
  "age": null,
  "notes": "",
  "tags": []
}
Cleaned
{
  "name": "Alice"
}

Features

  • Remove null values recursively through all nesting levels
  • Optionally strip empty strings, empty objects, and empty arrays
  • Output is auto-formatted and pretty-printed
  • Impact summary shows fields removed, breakdown by type, optional removed paths, and size reduction
  • Download cleaned JSON as a .json file
  • 100% private; no server, no upload

Frequently Asked Questions

What does a JSON cleaner do?

A JSON cleaner removes selected empty or unwanted values—such as nulls, empty strings, empty objects, and empty arrays—so payloads are easier to read, diff, and ship.

Can I remove null values from nested JSON?

Yes. This cleaner walks nested objects and arrays recursively and removes matching values at every depth when those options are enabled.

Why should I clean JSON before using it?

Cleaning reduces noise, improves readability, simplifies comparisons, and trims unnecessary fields before storage, export, or schema generation.

What counts as an empty value in JSON?

Depending on toggles, empty values can include null, empty strings (""), empty arrays ([]), and empty objects ({}). Only the categories you select are removed.

Will cleaning JSON break my data?

It depends on what you remove. If downstream code relies on a key being present—even when null—removing that key changes semantics. Review toggles and diff before/after output.

Should I format cleaned JSON afterward?

Yes. Use the JSON Formatter after cleaning to inspect the final structure with consistent indentation.

Can I compare cleaned JSON with the original version?

Yes. Paste before and after into JSON Diff or Compare JSON to verify exactly what changed.

Is my JSON uploaded when using the cleaner?

No. Cleaning runs entirely in your browser.

What is JSON cleanup and when do I need it?

JSON cleanup is the process of removing unwanted or empty values from a JSON payload to make it smaller and easier to work with. You need it when an API response contains too many null fields, when you want to trim a config file before committing it, or when you need to reduce payload size before sending data over the wire.

How do I clear all null values from JSON?

Paste your JSON, make sure the Remove nulls toggle is on, then click Clean. The tool walks every key at every nesting level and removes entries whose value is null. If you also want to remove empty strings or empty arrays, enable those toggles before running.

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