JSON to CSV converter
Turn an array of JSON objects into a CSV spreadsheet file.
Processed in your browser. This file is converted on your device and is never uploaded.
Converter
.json up to 25 MB. You can also drag a file here.
No file selected.
About this tool
CSV is the format spreadsheets, databases, and data tools accept everywhere, but APIs and configuration files almost always hand you JSON. This tool bridges the two: give it an array of JSON objects and it writes a CSV file with one row per object.
Column order follows the order keys first appear across the whole document, not just in the first object, so a field that only some records carry still gets its own column instead of being dropped.
Supported formats and limits
- Input
- .json
- Output
- .csv (text/csv)
- Output name
- The original name with the new extension, for example data.json becomes data.csv.
- File size limit
- 25 MB
- Processing
- In your browser. The file is not uploaded.
JSON against CSV
| Feature | JSON | CSV |
|---|---|---|
| Stored as | Plain text, readable in any editor | Plain text, readable in any editor |
| What it can hold | Values nested inside values | Rows and columns |
| Numbers stay numbers | Yes | No |
| Comments | No | No |
| Several in one file | No | No |
| Published | 2001 | 1972 |
How to use it
- Choose a .json file, or switch to Paste text and paste the JSON directly.
- Decide whether the first row should list the column names.
- Select Convert, then download the .csv file.
Limitations
- The top level must be an array of objects, such as [{"name":"Ada"},{"name":"Alan"}]. A single object is treated as one row. Arrays of plain values or numbers are rejected with an explanation.
- CSV is flat, so a nested object or array is written into its cell as JSON text rather than expanded into more columns.
- null and missing fields become empty cells. Once written, an empty cell cannot be told apart from an empty string.
- Types are lost. Everything in a CSV file is text, so numbers, booleans, and dates all arrive as strings when read back.
- Converting back with the CSV to JSON tool will not reproduce the original document exactly, for the two reasons above.
Common problems
The file was refused before anything started.
JSON to CSV converter checks the extension before it reads a byte, and it accepts .json. Browsers report file types inconsistently enough that the extension is what decides.
Rename the file if the extension is simply wrong, or convert it to one of those first. A file whose extension does not match its contents is refused for the same reason, and that one needs converting rather than renaming.
It said the file was too large.
The limit here is 25 MB. It is not a policy but a measurement: everything runs on your own device, and past that size a phone runs out of memory rather than finishing slowly.
Split the file, reduce it before converting, or use a desktop program for that one. A machine with more memory will manage more, but the limit does not know which machine it is on.
I selected several files and only one converted.
This tool takes one file at a time. Doing several at once would multiply the memory in use, which is the thing most likely to fail on a phone.
Convert them one after another. Nothing is kept between them, so there is no state to reset.
The tab reloaded itself part-way through.
The browser ran out of memory and restarted the page. At sizes approaching 25 MB this is the failure a phone hits first, and it looks like a crash rather than an error.
Try a smaller file, close other tabs, or run it on a computer. Nothing was uploaded or lost — the original file is untouched on your device.
The result opened in the wrong program.
The output is a .csv file, and your system opens that extension with whatever it was told to. Nothing about the conversion decides it.
Open it from inside the program you want, or change the default for .csv in your system settings. The file itself is correct.
Frequently asked questions
- Is my file uploaded?
- No. The conversion runs entirely in your browser. The file never leaves your device and no request carrying its contents is made.
- What happens to nested objects?
- They are written into a single cell as JSON text. Flattening them into columns like address.city would need naming rules that quietly break on arrays, so the structure is preserved verbatim instead.
- Why do some rows have empty cells?
- Every row gets every column found anywhere in the document. If a record does not have that field, its cell is left empty.
- Are commas and quotes inside my values handled?
- Yes. Any value containing a comma, a quote, or a line break is quoted and escaped according to the CSV convention, so it survives a round trip through a spreadsheet.
- Which line endings does the output use?
- Unix line feeds. If you need Windows line endings, run the result through the line endings tool.
- Do I need to install anything or create an account to use JSON to CSV converter?
- No, to all of it. JSON to CSV converter runs inside the browser you already have, with no sign-up, no download, no watermark on the result, and no cap on how many files you convert. There is nothing to uninstall afterwards either, because nothing was installed.
- Does JSON to CSV converter work offline?
- Once the page has loaded, yes. The conversion runs on your device, so it needs no connection to do the work. The first visit fetches the page and the code that does the converting; after that a lost connection stops nothing, and a converted file appears exactly as it would online.
- How large a file can JSON to CSV converter handle?
- The limit is 25 MB. It is a deliberate one rather than a technical ceiling: the real constraint is memory, and a file that decodes to more than the device can hold fails in a way that is hard to explain. Phones run out well before laptops do, which is why the limit is set where it is.
- Can I convert several files at once with JSON to CSV converter?
- Not here: this tool takes one file at a time, because what it does depends on choices you make about that particular file. Convert them one after another, or look at the batch converters in the same category, which are built for a folder at a time.