Header, quoting and UTF-8 handled for you
The column names come from the keys of the first object. Fields with commas, quotes or line breaks are wrapped in double quotes, and accents, Arabic and Japanese text came through intact in our test.
JSON to CSV Converter
Add a .json file that holds a list of flat records and get a CSV back. Nested values and a single top-level object are not supported.
To convert json to csv, add a .json file whose top level is an array of flat objects, keep CSV as the output and download the result. In our test, a 590 B file with 5 records became a 220 B csv with a header row and 5 data rows. A file with a nested object failed.
Transfers use HTTPS, and files converted on the free tier are deleted after 24 hours, so the result is not a long-term archive. Quality depends on the source file, so open the CSV file once before you share it.
FromJSONLossless
JSON (JavaScript Object Notation)
A text format for structured data built from objects, arrays, strings, numbers, true, false and null. It has no comments and no date type, and it forbids NaN and Infinity. It must be UTF-8 when exchanged between systems, and it is the usual format for web APIs. It is defined by RFC 8259 and ECMA-404, and files end in .json.
ToCSVLossless
CSV (Comma-Separated Values)
Comma-separated values, a plain text format in which each line is a row and a delimiter separates the fields. It has no data types, no styling and no official single standard, although RFC 4180 describes the most common conventions.
A flat JSON file of 5 records and 6 keys, 590 B, converted on indox.org
- JSONthe original, 5 records, 6 keys
- 590 B
- CSVfrom indox, header plus 5 rows, 6 columns
- 220 B
Why use indox to convert JSON to CSV?
Nothing to install, no script to write
The conversion runs on indox servers, so it works from any browser on Windows, Mac or a phone. We used it without an account. If you only need one export, you can skip writing Python, jq or PowerShell.
A plain answer about nested data
Most API responses contain nested objects or lists. This converter does not flatten them, and this page says so before you upload. A nested test file failed in our run.
What happens to your JSON
Stays
- Your original .json file, which is not touched
- The values, including accents and Arabic or Japanese text
- Commas, quotes and line breaks inside fields, written in quotes
- The order of the records
Changes
- Structure: objects become rows and the first object's keys become the header
- Types: numbers, booleans and null become plain text, with null as an empty cell
- Numbers: 8.0 became 8 and 1.50 became 1.5 in our test
- Nesting: nested objects and lists are not supported and the conversion fails
- File size: 590 B became 220 B in our test, because keys are written once
How do I convert JSON to CSV online?
- 1
Check that your JSON is a flat list
The top level must be an array, and each item must be an object whose values are strings, numbers, booleans or null. Open the file in a text editor and look for braces or square brackets inside the values.
- 2
Add the file and start the conversion
Drop the .json file on the box or choose it from your device, keep CSV as the output and start. In our test it took 3.2 seconds from the click to Completed.
- 3
Download the CSV and open it
Save the file and look at the header and a few rows. If you open it in Excel and non-English letters look broken, import it through Data, From Text/CSV and pick UTF-8 as the file origin.
What do I get from indox's JSON to CSV converter?
You hand over a JSON array of flat records and take away a CSV that follows the quoting rules of RFC 4180, ready for a spreadsheet, a database import or a BI tool. The page states which JSON shapes fail, so you find out before you upload.
- A header row built from your own keys
- Commas, quotes and line breaks inside fields quoted correctly
- Accents, Arabic and CJK text kept in UTF-8
- Unsupported shapes named up front, with a flatten-first route
What are the limits for JSON to CSV?
Size
The upload box shows the live size limit before you add a file. Signing in raises it; a paid plan does not change it.
Formats
JSON in, CSV out. Pick another output on the converter if you need a different format.
Privacy
Files are encrypted in transit over HTTPS and processed on indox infrastructure.
Deletion
Free-tier files are kept for 24 hours after the job finishes, then deleted automatically.
Limits worth knowing
- The top level must be an array of objects. A single object, an object that wraps the list under a key, or an array of plain values or arrays is not supported by the engine behind this converter. We saw this in a local test of the engine, not on indox.org.
- Nested objects and lists fail. Our nested test file, 239 B with one nested object and one list, showed Failed about 2.1 seconds after the click. The row showed no error text and no download.
- The header comes from the first object only. In a local test of the engine, a key that appears only in a later object was dropped without a warning, and a later object missing a key made the conversion fail. Give every object the same keys.
- The engine could not read a file that starts with a UTF-8 byte order mark, or an integer larger than the 64-bit range, in the same local test. Save the file without a BOM, and write very large IDs as strings.
- There are no options. We saw no delimiter, header or quoting setting, so the output is always a comma-separated file with a header row. We did not measure a file size limit; our test files were under 1 KB.
When the result is not what you expected
| What you see | Why | What to do |
|---|---|---|
| The row shows Failed and nothing downloads | The file has a nested value, a top-level object or another unsupported shape. The row gave no reason in our test | Check for braces or brackets inside values and flatten them, then convert again |
| A single object does not convert | The engine needs a list of records at the top level | Wrap the object in square brackets, or use the array inside it |
| Columns are missing from the CSV | The header comes from the first object, and keys found only later are dropped | Give every object the same keys, with null where there is no value |
| Letters look broken in Excel | The CSV is UTF-8 without a byte order mark | Import it with Data, From Text/CSV and choose UTF-8. For more tables, see XLSX to CSV |
| Nothing converts and the file starts with odd bytes | A UTF-8 byte order mark at the start of the JSON stopped the engine in a local test | Save the JSON as UTF-8 without BOM and try again |
What do the free and paid plans add?
Free
- All converters
- Daily credit refresh
- Email support
Basic
- Access to all features
- AI Extract
- Priority conversions
- Email support
Highest priority
Premium
- Everything in Basic
- Highest priority queue
- Priority support
Pay-As-You-Go
- No subscription
- Credits never expire
- Opt-in auto-refill
- Access to all features
Which conversions are close to JSON to CSV?
JSON vs CSV: what is the difference?
| Compared on | JSON | CSV |
|---|---|---|
| Structure | Objects and arrays can nest to any depth | Flat rows and columns only |
| Data types | Strings, numbers, true, false and null | Text only, no types |
| Header | Keys are stored with every value | One optional header row |
| Where it opens | APIs, code and editors | Spreadsheets, databases and BI tools |
| Typical use | Exchanging data between programs | Analysing and importing tabular data |
Who can use a JSON to CSV converter?
When to use it
- Opening a list of users, orders or log records from an API in Excel or Google Sheets.
- Preparing a flat JSON export for a database or BI import that accepts CSV only.
- Sharing a small data set with a colleague who does not read JSON.
- Checking the keys and values of a JSON file as a table, row by row.
Where can I read more about converting files?
Sources
- RFC 8259: The JavaScript Object Notation (JSON) Data Interchange FormatIETF
- RFC 4180: Common Format and MIME Type for Comma-Separated Values (CSV) FilesIETF
- dasel, the data selector and converterTomWright, GitHub
Facts checked on November 4, 2026
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JSON to CSV FAQs
How do I convert JSON to CSV?
Add a .json file whose top level is an array of flat objects, keep CSV as the output and download the result. The first object's keys become the header row.
What happens to nested objects and arrays?
They are not flattened, and the conversion fails. In our test, a file with a nested object and a list showed Failed with no download and no error text. Flatten the data first, for example into one value per key, then convert it.
What if my objects have different keys?
The header is taken from the first object. In a local test of the engine, keys that appear only in later objects were dropped, and a later object missing a key made the conversion fail. Add the missing keys to every object, using null for no value.
Why does Excel show broken characters in my CSV?
The CSV we downloaded is UTF-8 without a byte order mark. Excel can then read it as another encoding. Open it through Data, From Text/CSV and choose UTF-8 as the file origin. We did not test Excel itself.
Why does a single JSON object not convert?
The engine expects a list of records at the top level. Wrap your object in square brackets to make a one-item array, or take the array out of the wrapping object before you convert.
Does it work for large files?
We did not measure a size limit or the speed on large files. Our sample files were 590 B and 239 B. Keep in mind that Excel itself stops at 1,048,576 rows per sheet.
Are commas and quotes inside values handled?
Yes. In our test, a name with a comma and inner quotes was written in double quotes with the quotes doubled, and a field with a line break was quoted too, as RFC 4180 describes.
Can I convert CSV back to JSON, or script this instead?
This page converts in one direction only. If you need the same conversion many times, a short script with Python, jq or PowerShell in your own environment gives you control over nesting and column names.