Excel to JSON / CSV Converter Online

Read an .xlsx workbook into JSON rows or CSV (dates as ISO, header row as keys), or build a styled .xlsx file with several sheets from JSON.

Result

Press “Run” to see the result.

The Excel API works in both directions. Upload an .xlsx file and get the first visible sheet (or the one named in sheet, by name or index) as JSON objects keyed by the header row, as raw rows (format=rows) or as CSV (format=csv, UTF-8 with BOM so Excel reopens it correctly, delimiter=; for European Excel). Date cells are recognised from their number format and returned as 2026-11-11, booleans stay booleans, empty rows are skipped and duplicate headers get a suffix (Tên_2). list=sheets only lists the sheets, skip_rows skips a title block above the header and limit caps the rows returned.

Send JSON instead of a file to create a workbook: data (an array of objects or of arrays) for one sheet, or sheets ({"Sheet name": [...]}) for up to 20 sheets. Objects produce a bold, frozen header row with an auto filter; YYYY-MM-DD strings become real Excel dates (dd/mm/yyyy). The answer is the .xlsx file itself, named after filename.

Our own reader and writer run in memory: up to 1,000,000 cells when writing, 2,000,000 cells when reading, within the file size of your plan. Old .xls files are not supported (save them as .xlsx), and formulas are read as their last computed value.

Use this in your code

curl -X POST "https://apibox.io.vn/v1/xlsx-convert" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -F "0=@./my-file"

const form = new FormData();
form.append('0', fileInput.files[0]);

const res = await fetch('https://apibox.io.vn/v1/xlsx-convert', {
  method: 'POST',
  headers: { Authorization: 'Bearer YOUR_API_KEY' },
  body: form,
});
console.log(await res.json());

import requests

res = requests.post(
    "https://apibox.io.vn/v1/xlsx-convert",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
    files={"0": open("my-file", "rb")},
    timeout=30,
)
print(res.json())

<?php
$ch = curl_init('https://apibox.io.vn/v1/xlsx-convert');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_CUSTOMREQUEST => 'POST',
    CURLOPT_HTTPHEADER => ['Authorization: Bearer YOUR_API_KEY'],
    CURLOPT_POSTFIELDS => ['0' => new CURLFile('my-file')],
]);
$response = curl_exec($ch);
print_r(json_decode($response, true));

API documentation → Get a free API key

FAQ

Are formulas evaluated?

No: the value Excel saved with the file is returned. Files generated without cached values return the formula cells empty.

How are dates returned?

As ISO strings (2026-11-11, or 2026-11-11T08:30:00 with a time), detected from the cell number format.

Can I read a sheet other than the first?

Yes, sheet=<name> or sheet=<index> (0-based); list=sheets shows the names, including hidden sheets.