JSON to CSV
Paste JSON or open a UTF-8 JSON file to convert a flat object or non-empty array of flat objects to CSV locally in your browser.
Private, browser-local processingYour JSON is processed locally in your browser and is not uploaded to Savezly.
Supported JSON Shapes
Convert one flat JSON object or a non-empty top-level array containing only flat JSON objects.
Union of Columns
When rows have different keys, the CSV header uses the union of every key and later keys extend the columns.
Source Key Order
Columns follow each key's first lexical appearance in the JSON source, including integer-like keys, rather than alphabetical order.
Missing and Empty Values
A missing key and an empty JSON string both become an empty quoted CSV cell.
JSON Scalar Conversion
Strings are decoded, numbers keep their original JSON spelling, booleans become lowercase text, and null becomes the text null.
CSV Type Loss
CSV does not preserve JSON types: missing and empty strings can look alike, and JSON null and the string null can both become null.
Flat Values Only
Nested objects and arrays, including empty nested containers, are rejected instead of flattened or stringified.
Formula-Like Text Warning
Formula-like JSON string values are preserved unchanged and reported because spreadsheet applications may interpret some values as formulas or commands.
Private Local Conversion
Parsing, CSV generation, and verification run locally in a same-origin browser Worker without uploading your data.
Continue Working With Data
Copy or download the verified CSV, use CSV to JSON for the reverse conversion, or inspect source with the JSON Formatter & Validator.
Frequently Asked Questions
Is my JSON uploaded?
No. Conversion runs locally in your browser and your JSON is not uploaded to Savezly.
Which JSON roots are supported?
Use one flat object or a non-empty array containing only flat objects. Primitive roots and empty arrays are rejected.
Can rows have different keys?
Yes. The header is the ordered union of keys, and missing values become empty CSV cells.
How are columns ordered?
Columns follow the first lexical appearance of decoded keys in the JSON source.
Are JSON numbers changed?
No. Valid JSON number lexemes, including large integers, negative zero, decimals, and exponent notation, are preserved exactly.
Are JSON types preserved in CSV?
No. CSV contains text, so some distinctions such as null versus the string null are intentionally lost.
Are nested objects or arrays supported?
No. Values must be strings, numbers, booleans, or null; nested containers are rejected.
What does the formula warning mean?
Some spreadsheet applications may interpret certain leading characters as formulas or commands. Savezly preserves the original string text and shows an advisory warning.
What CSV format is generated?
The output uses commas, standard double-quote escaping, CRLF record separators, UTF-8, and no byte-order mark.
Can I copy or download the CSV?
Yes. After successful internal verification, you can copy the exact CSV or download it as a UTF-8 .csv file.