Sheet ReserveSpreadsheets worth keeping.

Formats

How are Sheet Reserve files converted in my browser?

Short answer

Each workbook is stored once on the server as compressed JSON. When you download, your browser receives that compressed copy, typically tens of kilobytes, and JavaScript on the page writes the XLSX, ODS, XML, CSV or Numbers file locally. No conversion server sees the file. Formulas and styles are kept in XLSX, ODS and XML; CSV holds values only.

Updated

Sheet Reserve does not keep a separate XLSX, ODS, CSV, XML and Numbers copy of every sheet. It keeps one, and your browser builds the format you choose at the moment you download.

What happens step by step when I download a Sheet Reserve file?

  1. Each workbook is stored once on the server, in a SQLite database, as compressed JSON. That JSON describes every tab, cell, formula, cached value, style, column width, merged range and frozen pane.
  2. When you click download, your browser receives that compressed copy. It is typically tens of kilobytes.
  3. JavaScript on the page reads the workbook and writes the file in the format you picked, on your own device. The finished file is saved by your browser like any other download.
  4. No conversion server is involved. The file is not uploaded, converted elsewhere and sent back.

Downloads therefore need JavaScript enabled in your browser. Access is still decided by your account and membership, as described in how the membership works.

What does each download format keep from a workbook?

Format What is kept
XLSX Formulas, cached values, styles, column widths, merged cells, frozen panes and all tabs
ODS The same as XLSX: formulas, cached values, styles, column widths, merged cells, frozen panes and all tabs
XML Formulas and styles in a single XML file (SpreadsheetML 2003)
CSV Values only, one file per tab; zipped when a workbook has several tabs
Numbers The cell values of the workbook

Numbers files are written with the open-source SheetJS library and contain the cell values of the workbook. For live formulas and full styling in Numbers, open the XLSX version instead, which Numbers imports.

Which download format should I choose for my workbook?

  • Use XLSX for Excel, Google Sheets, LibreOffice and Numbers when you want everything to work, including formulas. It is the best default.
  • Use ODS if you work in LibreOffice or OpenDocument-based tools and want to keep formulas and styling.
  • Use XML (SpreadsheetML 2003) if a program or script expects that older, single-file XML format.
  • Use CSV when you need the values only, for a database, a script or an import into another tool. Remember that CSV carries no formulas, so what you see is the cached value of each cell.
  • Use Numbers only if you want a native file for Apple's Numbers and are happy with values alone.

A longer comparison is in XLSX, CSV, ODS, XML or Numbers: which format to use. For the specifics of two common choices, see XLSX versus CSV and what is a Numbers file.

What should I know about CSV downloads and opening them in Excel?

  • Zip files for CSV. A workbook with several tabs downloads as a ZIP containing one CSV per tab, because the format cannot hold more than one table per file.
  • Opening CSV in Excel. If Excel puts everything in one column or drops leading zeros, the cause is usually how Excel imports the text, not what is in the file. The blog post on opening CSV in Excel without breaking data covers the fixes.
  • Trying it out. The two free sheets, monthly household budget and world countries geography, are available to any verified account, which makes them a way to compare the formats before deciding on a membership.
  • Rate limits. Fair-use rate limits apply to downloads. They exist to stop automated scraping, not to limit normal use.

If a downloaded file looks wrong in your spreadsheet program, write to [email protected] with the format, the program and its version.