Excel Converter is for opening a spreadsheet in the browser, taking one look at it, and turning it into something else: xlsx, xls and csv go out as XLSX, CSV, JSON, an HTML table or a Markdown table, and in the other direction a pasted JSON array becomes an .xlsx. Parsing and writing are both done by SheetJS inside the browser, and a workbook with several sheets can be exported one tab at a time.

It is a format changer, not an online spreadsheet editor. To print a sheet as PDF, click “Convert to PDF (new tool)” to hand the current file over to “Excel to PDF”; and if you only want to flick through a large table on a phone, “Excel and CSV Viewer” is lighter.

1. 01Upload a spreadsheetdrop in .xlsx, .xls or .csv (CSV must be UTF-8, otherwise it reports a parse failure), and the sheet count comes back.
2. 02Preview the data“Data preview” shows the first 100 rows by 50 columns with A, B, C column headers and row numbers; with several sheets, tabs at the top switch between them and the active tab is what gets exported.
3. 03Export“XLSX” writes every worksheet; “CSV (UTF-8 BOM)”, “JSON”, “HTML table” and “Markdown table” cover the active sheet only, and “Copy Markdown” goes straight to the clipboard; with several sheets the file name gains _<sheet name>. The JSON shape can be “array of objects (first row as keys)” or “array of arrays”.
4. 04JSON to Excelpaste an array of objects or an array of arrays at the bottom, click “Generate Excel” and download data.xlsx (a single Sheet1).

Input

one .xlsx, .xls or .csv file; CSV is decoded as UTF-8 only, so a GBK CSV comes out as mojibake or fails — run it through “Text Encoding Converter” first.

Preview

the first 100 rows and 50 columns are shown; anything beyond that is not previewed but does export; what you see is formatted text (dates and percentages follow the cell format).

Export content

formula cells export their calculated result, not the formula; merged cells, column widths, fonts, colours, conditional formatting and charts are not preserved; in a Markdown table vertical bars are escaped and line breaks become <br>.

JSON to Excel

only a JSON array is accepted — an array of objects takes each object's keys as headers, an array of arrays is written row by row; a nested object is written as [object Object], so flatten it first.

What it does not do

it does not edit cells, does not merge several files and does not produce PDFs (click “Convert to PDF (new tool)”); for JSON, YAML, XML and CSV conversion use “JSON, YAML, XML and CSV Converter”.

Spreadsheets and pasted JSON are parsed and generated locally in the browser, and the content is never uploaded to any server; the data leaves memory when the page is closed.