Convert JSON to CSV, Free
Files convert instantly in your browser. 100% private, any file size, no account needed.
How to convert JSON to CSV
JSON is the standard format for API responses and data exchange between web applications, but its nested structure makes it difficult to analyze in a spreadsheet. CSV is flat by nature and opens directly in Excel, Google Sheets, and any data analysis tool. Converting JSON to CSV is a common step when pulling data from an API and handing it off to a non-technical colleague or importing it into a database.
BoltConverter flattens your JSON array of objects into CSV rows on its servers. Each key in the JSON objects becomes a column header, and each array item becomes a row. Nested objects are serialized as strings in the corresponding cell.
Upload your JSON file
Click the upload area or drag your .json file onto the page. Files up to 100 MB are accepted.
Conversion runs on the server
BoltConverter parses the JSON array and maps each object to a CSV row with consistent column headers.
Wait a moment
Most JSON files convert in seconds. Large files with many records may take a little longer.
Download the CSV
Click Download to save the CSV. Your JSON file is deleted from the server after conversion.
Frequently asked questions
What JSON structure works best for conversion to CSV?
The converter works best with a top-level JSON array of objects where each object has the same keys. For example: [{"name":"Alice","age":30},{"name":"Bob","age":25}].
What happens to nested objects?
Nested objects and arrays within a JSON record are serialized as a string in the CSV cell. If you need nested data flattened into columns, you will need to preprocess the JSON.
What if my JSON objects have inconsistent keys?
The converter collects all unique keys across all objects and uses them as column headers. Objects missing a key will have an empty cell in that column.
Is my data kept private?
Your JSON file is sent over HTTPS and deleted from the server immediately after conversion. BoltConverter does not retain or analyze your data.
Can I open the CSV directly in Excel?
Yes. The output CSV uses UTF-8 encoding and comma separation, which opens correctly in Excel, Google Sheets, and LibreOffice Calc.