JSON to XLSX converter
Turn an array of JSON objects into an Excel workbook, one row per object.
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
API responses and exported records usually arrive as JSON, but the person who needs to read them usually wants a spreadsheet. This tool turns an array of JSON objects into an Excel workbook with one row per object.
Columns come from the union of every object's keys in the order they first appear, so a field that only some records carry still gets a column of its own.
Supported formats and limits
- Input
- .json
- Output
- .xlsx (application/vnd.openxmlformats-officedocument.spreadsheetml.sheet)
- Output name
- The original name with the new extension, for example data.json becomes data.xlsx.
- File size limit
- 25 MB
- Processing
- In your browser. The file is not uploaded.
JSON against XLSX
| Feature | JSON | XLSX |
|---|---|---|
| Stored as | Plain text, readable in any editor | A ZIP of XML parts, needs software |
| What it can hold | Values nested inside values | Rows and columns |
| Numbers stay numbers | Yes | Yes |
| Comments | No | Yes |
| Several in one file | No | Yes |
| Published | 2001 | 2007 |
How to use it
- Choose a .json file, or switch to Paste text and paste the JSON directly.
- Name the worksheet and decide whether the first row should list the column names.
- Select Convert, then download the .xlsx workbook.
Limitations
- The top level must be an array of objects. A single object is treated as one row; arrays of plain values are rejected with an explanation.
- Nested objects and arrays are written into their cell as JSON text, because a spreadsheet cell cannot hold a structure.
- Every cell is written as text, so numbers and dates arrive as text rather than numeric or date cells.
- The workbook has one worksheet, and no formatting, widths, or formulas are applied.
- Worksheet names cannot contain : \ / ? * [ ] and are limited to 31 characters, which is an Excel restriction.
Common problems
The file was refused before anything started.
JSON to XLSX 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.
Nothing happened for a long time on the first run.
JSON to XLSX converter downloads a library before it can begin, and it is fetched once and then reused. That wait is before the conversion rather than during it, which is why the progress bar sits still.
Leave the tab open and in the foreground; a background tab is throttled by the browser. Every conversion after the first one in a session skips this.
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 .xlsx 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 .xlsx 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 such as address.city needs naming rules that break as soon as arrays are involved, so the structure is preserved verbatim instead.
- Why do some rows have empty cells?
- Every row gets every column found anywhere in the document. Where a record does not have that field, the cell is left empty.
- Can I get numeric cells instead of text?
- Not from this tool. Converting values by guessing their type is how spreadsheet imports damage data, so the conversion is left to you in the spreadsheet application, where you can check the result.
- Do I need to install anything or create an account to use JSON to XLSX converter?
- No, to all of it. JSON to XLSX 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 XLSX 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 XLSX 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 XLSX 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.