JSON to CSV Converter
FileFlip converts JSON to CSV entirely inside your browser, using the text engine compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert a JSON file to CSV?#
- Drop your JSON file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to CSV and the conversion starts on its own. FileFlip downloads nothing at all, because everything it needs is already built into your browser, then runs the text engine on your own machine.
- Save the CSV file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting JSON to CSV lose quality?#
No. Converting JSON to CSV writes the data out again without discarding any of it, so nothing that was in the JSON file is lost on the way. What changes is the size of the file, not what is inside it.
Is it safe to convert JSON files online?#
Yes, because nothing is uploaded. FileFlip converts JSON files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What JSON to CSV actually does to the file#
Converting JSON to CSV runs on the text engine, downloads nothing at all, because everything it needs is already built into your browser, writes the data out again without discarding any of it, and drops comments and value types.
| Engine | the text engine |
|---|---|
| Conversion path | One step: JSON → CSV |
| Downloaded to your browser | Nothing. Your browser already has everything this conversion needs |
| Quality | Lossless |
| You get back | One file |
| Where it runs | On the page's own thread, so a very large file will make the tab wait |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Comments | Dropped | The target format has nowhere to put it. |
| Value types | Dropped | The target format has nowhere to put it. |
Worth knowing before you start:
- only a list of records can be written as a table; anything else is refused
- nested objects and arrays have no cell to sit in and are flattened to text
- this conversion runs on the page's own thread, so a large file will freeze the tab while it works
What is a JSON file?#
A JSON file holds data as nested objects and arrays built from strings, numbers, booleans and null, and nothing else, written in the syntax JavaScript uses for object literals.
Reach for JSON when data moves between programs and nobody needs to hand-edit it, since every language parses it the same way.
Convert JSON to YAML or TOML when a person needs to edit the file directly and wants comments, or to CSV when a spreadsheet or a script expecting rows is the destination.
What is a CSV file?#
A CSV file holds a table as one line of text per row, with values on each line separated by commas, and no single formal specification that every producer of the format agrees on.
Use CSV to move a flat table between spreadsheets, databases and scripts, where every consuming tool already knows how to read it.
Convert CSV to JSON when the data needs to travel into an API or a program expecting typed, nested structures instead of a flat table of strings.
JSON to CSV questions people ask#
What happens when I convert a JSON array of objects to CSV?
Converting JSON to CSV only works cleanly when the JSON is a flat array of objects sharing the same keys, because CSV has no way to represent nesting. A nested object or array inside a field gets flattened with a naming convention like address.city, stringified as JSON text inside one cell, or dropped, depending on which tool is doing the conversion.
Why doesn't JSON support comments?
JSON has no comment syntax by design. Douglas Crockford, who specified JSON, has said he removed comments deliberately after seeing people use them to hold parsing directives that broke interoperability between tools. A config file written in JSON that needs to explain itself either adds a plain key like _comment by convention, or moves to a JSON superset like JSON5 or JSONC, which aren't plain JSON.
Does JSON have a date type?
No, JSON has no date or time type. Dates in JSON files are always strings, most often ISO 8601 like 2026-08-26, or Unix timestamps written as numbers, and which convention a given API uses is something you have to check rather than infer from the format itself.
What happens to a JSON object when I convert it to XML?
A JSON object's keys become XML elements when converted to XML, since JSON has no equivalent of an XML attribute and the converter has to pick elements for everything. A JSON array needs a wrapper element plus a repeated child element to become valid XML, both of which JSON's own syntax never required.