Turn JSON files into Excel documents in a couple of clicks — the file you get is a .xls, which is what Excel saves and opens. The default data interchange format for APIs. Content is preserved and the layout is rebuilt for the target format.
Drop your files here
JSON files (.json) · up to 100 MB each
or paste files from your clipboard
Ready when you are
Drop a JSON file above and FileTools360 will turn it into XLS — right here on your device, without uploading anything.
Drag them onto the drop area, choose them from your device, or paste them from your clipboard. You can queue several at once. Nothing is sent anywhere — the file stays on this device.
The defaults suit most people. Open Advanced to control delimiter and header handling.
Press Convert. Everything happens on your own device — nothing is uploaded. Download files one by one, or grab them all as a ZIP.
Privacy, in plain words
What “uploaded” normally means. On most online converters, pressing the button copies your file across the internet onto a computer owned by that website. That copy is what the word “upload” means, and it is the part nobody explains.
What happens instead. This site does not do it. There is no server here that receives files, so your JSON file is read, converted and handed back by the browser you are using right now. It never travels — so there is no copy to store, read, leak or hand over.
Check it yourself in ten seconds
Turn off your Wi-Fi after this page has loaded, then convert a file anyway. It still works, because everything needed is already on your device.
The longer explanation of how this works, and the full detail of what is and is not stored on the privacy page.
A CSV or JSON export is personal information in bulk — the format is boring, and what is in it usually is not. It matters more than it sounds, because of what data files usually are:
Configuration files
these are where credentials get left by accident
Customer exports
every record your CRM holds, in one file
Survey responses
answers people gave on the understanding they were private
Logs and API dumps
identifiers, IP addresses, sometimes tokens
A file that is never sent cannot be kept, leaked, subpoenaed or used to train anything. That is a property of how this works, not a promise about how carefully it is run.
JSON represents structured data as nested objects and arrays. It came from JavaScript but is now the default interchange format for essentially every web API.
The pre-2007 Excel format is a binary structure limited to 65,536 rows and 256 columns — limits modern datasets routinely exceed.
The two formats solve different problems, which is why converting between them involves trade-offs rather than a straight upgrade.
| Property | Source | Target |
|---|---|---|
| Compression | None | None |
| Introduced | 2001 | 1987 |
| Browser support | Every modern language and tool. | Still opens in Excel and LibreOffice. |
People make this switch when they run into the limits of JSON: large flat tables, where CSV is smaller and simpler. XLS is the better fit when a legacy system demands it specifically.
The content survives; the layout is rebuilt. Text and the order it is read in carry across, but XLS lays the page out again rather than reproducing JSON's exact positioning, so line breaks, page breaks and spacing will differ. Anything that depends on precise placement is worth checking in the result.
On every sample measured, the XLS came out larger — 2.4× larger at best and 4.4× larger at worst.
| Sample | JSON in | XLS out | Change |
|---|---|---|---|
| A plain tableTen rows of flat records — the shape almost every spreadsheet export actually has. | 1.3 KB | 5.0 KB | 4.0× |
| Many columnsForty columns across three rows. Column-heavy data is where per-cell overhead shows up. | 3.1 KB | 7.5 KB | 2.4× |
| Nested recordsObjects inside objects. This is the shape that cannot survive a flat format intact, and the one that triggers a warning. | 1.3 KB | 4.5 KB | 3.6× |
| Commas and quotation marksText fields containing the delimiter and the quote character — where an escaping bug would show. | 1.2 KB | 5.5 KB | 4.4× |
Produced by this site's own converter. The same code that runs in your browser, at the same default settings, so these are the bytes you would download.
Samples are generated from a fixed seed rather than taken from real photographs or documents, so the corpus is reproducible and carries no licensing question — and so the numbers predict the shape of your result rather than its exact size. Measured 2026-10-01. The method, and the command that regenerates every figure on this page, are on the how it works page.
Source
The default data interchange format for APIs.
Target
Excel's pre-2007 binary workbook.
Good to know
Runs entirely in your browser
527 converters and tools65 file formatsnothing ever uploaded.