One CSV per sheet, no clicking through tabs
Excel's own "Save as CSV" exports only the active sheet, and warns you about it every time. Tinyvert reads the whole .xlsx and writes one CSV for every sheet it contains. A workbook with Orders, Customers and Lookup tabs gives you three files, each named after its sheet and listed under the row with its own download button; "Download all" packs them into a ZIP assembled on your device.
How each cell type is written
| Cell | In the CSV |
|---|---|
| Number | The stored value, as plain digits |
| Date | 2026-03-14, with the time when the cell has one |
| Boolean | TRUE / FALSE |
| Formula | Its last calculated result |
| Text | Unchanged, UTF-8 |
Dates deserve a word. Inside a workbook a date is a serial number with a display format, and that format follows the locale of whoever saved the file: 03/14/2026 to an American, 14/03/2026 to everyone else. Writing ISO 8601 removes the ambiguity, and databases, pandas, R and every scripting language parse it without a format string. A sheet like this:
date | order_id | total | paid
14 Mar 2026 | 10021 | £149.50 | TRUE
15 Mar 2026 | 10022 | £80.00 | FALSEexports as:
date,order_id,total,paid
2026-03-14,10021,149.5,TRUE
2026-03-15,10022,80,FALSEWhy people export Excel to CSV
Spreadsheets are where data gets collected; CSV is where it gets used. A CSV loads into PostgreSQL with COPY, into pandas with one line, into BigQuery, Mailchimp, a CRM import screen or a Git repository where diffs are readable. It also outlives any particular version of Excel, which makes it a sensible archival format for finished reports.
Choosing a delimiter
Comma is the default and what most programs expect. Choose Semicolon if the file is going back into Excel on a machine set to a European locale, where the comma is the decimal separator. Choose Tab for tools that want .tsv-style input, or when the data itself is full of commas and you would rather avoid quoting.
What is not carried over
CSV is plain text, so cell colours, column widths, merged cells, charts, comments and validation rules have nowhere to go and are dropped. The old binary .xls format and password-protected workbooks are not supported. Everything else happens in your browser: the file is read into memory, converted and offered for download, with no upload and no copy kept. Need the workbook as JSON instead? Try Excel to JSON. Going the other way, CSV to Excel rebuilds a workbook with typed cells, and CSV to JSON takes the exported file into code.