JSON Data Cleaner
Tidy up JSON from APIs, exports or forms in one step. The cleaner trims spaces in every string, removes invisible characters such as zero-width spaces, drops null, empty and placeholder values (N/A, NULL, “-”), removes empty objects and arrays, and can convert strings like "42", "true" and "null" into real numbers, booleans and null. Optionally it removes duplicate array items and sorts object keys, then outputs indented or minified JSON with a report of every change.
- Runs in your browser
- No sign-up
- Free to use
Processed entirely in your browser – your data is not uploaded. Files up to 50 MB.
How to use JSON Data Cleaner
- Paste JSON or open a .json file.
- Choose the cleaning rules.
- Click Clean JSON.
- Copy or download the cleaned JSON.
JSON Data Cleaner features
Deep cleaning
Works through nested objects and arrays.
Type conversion
Numbers, booleans and null from strings.
Safe numbers
Leading zeros (postcodes) stay strings.
Change report
Counts of every change.
Indent or minify
2, 4 spaces or one line.
Private
Runs in your browser; nothing is uploaded.
When to use JSON Data Cleaner
- Cleaning API responses.
- Preparing JSON for imports.
- Removing empty fields before storage.
- Normalising form submissions.
JSON Data Cleaner FAQ
Is the order of keys kept?
Yes, unless you choose to sort keys.
Will “007” become 7?
No – values with leading zeros are kept as strings.
Does it validate JSON?
Invalid JSON is reported with the parser’s message; use the JSON validator for details.
Will it change the structure of my JSON?
Only by removing empty values and objects you choose to drop. Keys and nesting are otherwise kept.
Will it remove zero and false values?
No. Zero and false are real values and are kept. Only null, empty strings, placeholders you choose and empty objects or arrays are removed.
Can I clean very large JSON files?
Files of several megabytes work in most browsers. Very large files depend on your device’s memory.
Clean data, fewer bugs
Empty strings, “N/A” placeholders and numbers stored as text cause bugs in code and wrong totals in reports. Cleaning once at the boundary keeps downstream systems simple.
JSON from APIs, form tools and exports often contains noise: strings with leading spaces, invisible zero-width characters, null values, empty strings and placeholders such as N/A. The cleaner removes them in one step and can drop objects and arrays that become empty.
Optional conversions turn numeric strings into numbers and “true”/“false” strings into booleans, which avoids type errors in the next system. Check the result once – an identifier like “00123” must stay a string, or the leading zeros are lost.
Cleaning runs in your browser and nothing is uploaded, so the tool is safe for data containing personal information.
Run the cleaner before importing JSON into a database, spreadsheet or analytics tool, and keep the original file. If you clean the same kind of export regularly, note the options you used so the result is identical every time.