Spreadsheets

About these tools

Convert workbooks to and from CSV, JSON, and XLSX without installing Excel or sending a file to a website. The workbook is parsed in your browser, so financial models, payroll exports, and customer lists stay on your machine.

A spreadsheet is not a flat table, and these tools are explicit about that: you choose which worksheet to export, and each tool's page states what happens to formulas, formatting, and dates.

A spreadsheet file is not a table. An .xlsx is a ZIP of XML parts holding worksheets, formulas, number formats, styles, merged cells and often a chart or two. A CSV is a grid of text. Everything in the first list that is not a value disappears on the way to the second, and no converter can do otherwise — which is why these tools tell you what will be lost before you convert rather than after.

What survives is the values, and that is usually what you wanted: a workbook is how a person edits data and a CSV or JSON file is how a program reads it. Formulas come across as the numbers they last evaluated to, because that is what is stored in the file. Dates are where care is needed, since a spreadsheet keeps them as numbers with a format attached, and the tools here say plainly how they are written out.

Frequently asked questions

Can I convert Excel to CSV without Excel?

Yes. Open the XLSX to CSV converter, choose your workbook, and pick the worksheet you want. No spreadsheet application is involved and nothing is uploaded, which is the usual reason people look for a converter in the first place.

What happens to my formulas?

The calculated values are exported, not the formulas. CSV and JSON have no concept of a formula, so what you get is the numbers the workbook was showing. If you need the formulas themselves, keep the .xlsx.

Does it handle workbooks with several worksheets?

Yes. The tool reads the workbook first and lets you choose which sheet to export, because guessing wrong on a workbook with a summary tab and twelve monthly tabs is worse than asking.

Are my dates converted correctly?

Yes, and this is a place many converters get it wrong. Spreadsheet dates are stored as numbers, and converting them through a timezone can shift them by a day. These tools format dates from their own components, so a date exported in Sydney is the same date it was in the workbook.

Does it support old .xls files?

The tools target .xlsx, the format Excel has produced by default since 2007. If you have a legacy .xls, open it in any spreadsheet application and save it as .xlsx first.

Is my workbook uploaded anywhere?

No. The spreadsheet engine is JavaScript that runs in your browser. Your workbook is read from disk into memory, converted, and released. Nothing is transmitted and nothing is stored.

What about formatting, colours, and merged cells?

They do not survive, because CSV and JSON cannot express them. What you get is the data. If the presentation matters, keep the original workbook alongside the export.

Can I convert a CSV back into a real Excel workbook?

Yes, and it is a genuine .xlsx rather than a CSV with the extension changed, which is what Excel complains about when somebody renames one. You name the worksheet, and the result opens without the warning dialogue. Going the other way, one worksheet or every worksheet can come out as CSV.

Are numbers stored as text after conversion?

Going out to CSV, everything becomes text, because CSV has no way to record that a value was a number. Going into XLSX or JSON, types are preserved as the workbook had them. That asymmetry is why a round trip through CSV can turn a postcode into a number, and why the CSV tools here never guess types back.

How large a workbook can these handle?

The limit is stated on each tool's page, and the real constraint is memory rather than rows: a workbook is decompressed and held in full while it is read, so the ceiling is what the device can hold rather than a row count. Phones run out well before laptops, which is worth knowing before converting a year of records on one.