XLSX to JSON converter
Turn a worksheet into an array of JSON objects, with control over blank cells.
Processed in your browser. This file is converted on your device and is never uploaded.
Converter
.xlsx up to 25 MB. You can also drag a file here.
No file selected.
About this tool
Turning a spreadsheet into JSON is usually the first step in feeding a workbook into an API, a script, or a database. This tool opens an .xlsx workbook in your browser and writes a chosen worksheet as an array of JSON objects, one per row.
Because blank cells and dates are exactly where spreadsheet exports usually go wrong, both are yours to decide rather than being guessed at.
Supported formats and limits
- Input
- .xlsx
- Output
- .json (application/json)
- Output name
- The workbook name with the worksheet name appended, for example budget.xlsx becomes budget-Q1.json. Exporting every worksheet produces budget-sheets.zip.
- File size limit
- 25 MB
- Processing
- In your browser. The file is not uploaded.
XLSX against JSON
| Feature | XLSX | JSON |
|---|---|---|
| Stored as | A ZIP of XML parts, needs software | Plain text, readable in any editor |
| What it can hold | Rows and columns | Values nested inside values |
| Numbers stay numbers | Yes | Yes |
| Comments | Yes | No |
| Several in one file | Yes | No |
| Published | 2007 | 2001 |
How to use it
- Choose an .xlsx workbook. Its worksheets are listed as soon as it is read.
- Pick a worksheet, or choose to export all of them.
- Say whether the first row holds column names, and choose how blank cells and dates should be written.
- Select Convert, then download the .json file or the .zip archive.
Limitations
- Every value is written as a string, except blank cells when you ask for null. Numbers are not converted to JSON numbers, because doing so silently damages values such as postcodes, long account numbers, and version strings.
- Formulas are not recalculated; the value saved with the workbook is used.
- Formatting, merged cells, charts, images, and comments are not represented.
- Duplicate column names collapse, and the last column with a given name wins.
- Only .xlsx is supported. Older .xls and macro-enabled .xlsm files are rejected.
- Password-protected workbooks cannot be opened.
Common problems
The file was refused before anything started.
XLSX to JSON converter checks the extension before it reads a byte, and it accepts .xlsx. 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.
XLSX to JSON 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 .json 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 .json in your system settings. The file itself is correct.
Frequently asked questions
- Is my workbook uploaded?
- No. The workbook is opened and converted entirely in your browser. It never leaves your device and no request carrying its contents is made.
- Which empty-cell setting should I use?
- Use null when the consumer distinguishes a missing value from an empty one, leave the property out when it expects optional fields, and use an empty string when it expects every key to be present as text.
- Why are my numbers quoted?
- Cell values are written as text so nothing is lost in translation. A number that has to be a JSON number is a small transformation after conversion, whereas a corrupted account number cannot be recovered.
- Can I convert every worksheet at once?
- Yes. Choose all worksheets and the download is a ZIP archive with one JSON file per sheet, named after the sheet.
- Do I need to install anything or create an account to use XLSX to JSON converter?
- No, to all of it. XLSX to JSON 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 XLSX to JSON 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 XLSX to JSON 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 XLSX to JSON 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.