Excel and OpenDocument, opened as data.

Workbooks, read as the data they hold

An .xlsx opens with its shared strings, rich text, formula results, date formats and skipped rows and columns understood — and so do .xlsm, .xltx and .xltm. The workbooks Excel wrote until 2007, .xls, open too, and so does the binary .xlsb that large files are often handed over in. An OpenDocument .ods opens with its repeated rows and columns expanded. A workbook with several sheets asks which of them to open, and each one chosen opens as a tab; the window says which sheet is on show and what else the workbook holds.

What looks like a number in a text cell stays text: an article number stored as 00731 in the workbook is 00731 in the grid.

A workbook goes back as itself

Open an .xlsx, edit it and press ⌘S: the file you opened is rebuilt with every part it arrived with. Its other sheets, its column widths, its merged cells, its defined names, its charts and its number formats are all kept, and only the rows of the sheet you edited are replaced — so a date stays a date and a price stays a price. A macro workbook keeps its macro project byte for byte, so .xlsm files edit and save like any other.

Two things are worth knowing, because Intact CSV Editor is a data editor rather than a spreadsheet:

• A formula on the sheet you edited comes back as the value it last calculated. Formulas on every other sheet are untouched.
• .xls, .xlsb and .ods are read, not written in place: saving one writes a copy — as .xlsx or any other format — and the original stays exactly as it was.

HTML tables from a web page

Open a saved web page and the app lists the tables in it, with their size, and opens the ones you choose — each as a document of its own. A table copied from a browser pastes in as rows and columns. Markdown pipe tables open too.

Export to Excel

Any table — a CSV, a Parquet file, a SQL result — exports to .xlsx with a sheet name and a frozen header row, or to .ods for LibreOffice and Numbers. A million rows go out in seconds, and a code Excel would ruin — a leading zero, a plus, eighteen digits — goes into the workbook as text, every digit of it. Copy a selection as HTML and paste it into Excel, and the same codes arrive as text there too. Two presets are built in: Excel (European) and Excel (US) for the CSV files each flavour of Excel expects.