Excel to CSV or JSON: Export the First Sheet

First Worksheet Only

Spreadsheets carry far more than data: column widths, cell colours, charts, validation rules, macros. When you need to move the values into a database, a script, or another system, most of that is in the way. This tool reads a workbook and exports the values from one worksheet as CSV (a plain text table) or JSON (structured data for code). The most important thing to know first: only the first worksheet is exported — not the sheet you had open when you saved, but the first one in the workbook's own order.

Open Excel to CSV / JSON

When this tool is useful

Importing a list into another system: CRMs, e-commerce platforms, and mailing tools almost universally accept CSV and rarely accept XLSX directly.
Feeding data into a script: a Python or JavaScript program is far simpler to write against CSV or JSON than a spreadsheet format.
Loading rows into a database: bulk import tools expect delimited text.
Passing data to someone with no Excel: CSV opens in any text editor, on any system, without licensed software.
Building a small data file for a web page: JSON is what browser code expects, and a short lookup table is quicker to export than to hand-type.

How the export works

The tool uses SheetJS, a JavaScript library that reads spreadsheet formats in the browser. Your workbook is parsed, and the tool takes the first worksheet — always the first, with no selector and no detection of which sheet was active when you last saved — and reads its cell values. For CSV, those values are written as lines of text with commas between cells. For JSON, they are assembled into nested arrays and formatted with two-space indentation.

What gets read are values, not the machinery that produced them. If a cell contains a formula, what comes out is the result stored in the file. This tool does not recalculate anything; it is not a spreadsheet engine. A workbook saved with stale results will export those stale results.

What the JSON actually looks like

JSON output is an array of row arrays, worth seeing rather than describing. A small sheet with a header row Region, Units, Opened and two data rows exports as:

[
  [
    "Region",
    "Units",
    "Opened"
  ],
  [
    "North",
    120,
    "2026-01-14"
  ],
  [
    "South",
    95,
    "2026-01-15"
  ]
]

Note what this is not: it is not an array of objects keyed by your header row. There are no {"Region": "North"} structures. The header row is simply the first array in the list. Numeric cells come through as JSON numbers (unquoted, like 120), while text stays quoted. If your code expects keyed objects, take the first array as your keys and map the rest against it, a few lines you write yourself.

Step by step

Put your data first

Check which sheet sits first in the workbook. If the data you want is elsewhere, drag its tab to the front and save.

Pick a format

Select one .xls or .xlsx file and choose CSV (the default) or JSON before converting.

Check the awkward columns

Open the file and inspect dates, reference numbers with leading zeros, long numeric IDs, and anything containing commas.

CSV or JSON: which to pick

Choose CSV when

The data is going into another application that imports tables: a CRM, a mailing platform, an accounting package, a database import wizard, or another spreadsheet. CSV is the universal exchange format for tabular data, readable by effectively everything. Its filename follows your source, so sales-q1.xlsx becomes sales-q1.csv.

Choose JSON when

The data is going into code. Web applications, APIs, and scripts consume JSON natively, without parsing delimiters or worrying about quoting rules. The nested-array structure maps directly to a two-dimensional list in most languages. A rough guide: if a human opens the file in a spreadsheet program, use CSV; if a program reads it, use JSON.

Data types to check after conversion

Dates may export in a different form than Excel displayed, since display formatting and stored value are separate things.
Leading zeros on reference codes and postcodes can be lost if the cell held the value as a number.
Long numeric IDs may have been stored in a form that loses precision.
Values containing commas need correct quoting in CSV to survive import, so check that any free-text column came through intact.

Important limitations

Only the first worksheet is exported: no sheet selector, no multi-sheet export, no batch processing of several workbooks.
This exports values, not a workbook: charts, images, pivot tables, macros, conditional formatting, validation rules, comments, merged cells, and styling are all outside what CSV or JSON can carry.
Formulas are not preserved as formulas: you get whatever result was stored when the file was saved.
CSV has no formatting layer: no colours, no column widths, no multiple sheets. That is the format doing its job, not a fault.
Encrypted or damaged workbooks may fail: the library needs to read the file.

Privacy and data handling

File contents are processed in browser memory and are not sent to WeConvertFiles for conversion. The SheetJS library is downloaded from a third-party CDN when needed, so the workflow is not described as fully offline.

Zoho PageSense may collect consented site-usage data such as visits, clicks, scrolling, referrer, device information, and conversion events. PageSense is not given the selected workbook contents.

Troubleshooting

The wrong data came out

The workbook's first sheet was not the one you wanted. Reorder the tabs in Excel so your data sits first, save, and convert again.

Dates look wrong or appear as numbers

Spreadsheets store dates as numbers and apply a display format on top. The export takes the stored value, so convert the column to text in a copy of your workbook before exporting if the exact displayed form matters.

Leading zeros have disappeared

The cell contained a number, and numbers have no leading zeros. Format the column as text in your workbook before exporting.

A formula result looks out of date

The export reads what the file stored. Open the workbook, let it recalculate, save, and convert again.

A text column split across several CSV columns

The values contain commas and were not quoted as your importing application expects. Check the raw file in a text editor to see how the values were written.

Frequently asked questions

Can I choose which worksheet to export?

No. The first worksheet in the workbook is always used, regardless of which sheet was active when the file was saved. Reordering the tabs in Excel so your data sits first is the only way to change what gets exported.

Why is the JSON not keyed by my column headers?

The export produces plain nested arrays, with the header row appearing as the first array. Turning that into keyed objects is straightforward in code, but it is a step you write yourself rather than something the tool performs.

Does the tool calculate my formulas?

No. It reads the values stored in the file. A browser tool is not a spreadsheet calculation engine, so anything depending on recalculation should be sorted out in Excel before you export.

Will my column widths and cell colours survive?

No, and they could not. CSV and JSON are data formats with no concept of presentation. If you need the workbook's appearance preserved, converting it to PDF keeps the layout as a fixed document.

Does .xls work as well as .xlsx?

Both are accepted. The .xls format is the older binary one and .xlsx the modern one; the library reads either, and the export is the same in both cases.

Is my original workbook modified?

No. The file is read and a new export is produced. Nothing is written back to your spreadsheet.

Related tools

Word or Excel to PDF

When you need the sheet's appearance preserved for reading rather than its values extracted for processing.

PDF to Word / TXT

When the data you need is trapped in a PDF rather than a workbook, this pulls out the text it contains.

Get portable data out of a workbook

Put your data on the first sheet, choose CSV or JSON, and download a clean file named after your workbook, with the original left untouched.

Use Excel to CSV / JSON