About the Online Excel / Spreadsheet Editor
Edit XLSX, CSV and TSV spreadsheet data online. Paste multiple cells, enter basic formulas, add rows and worksheets and export a workbook.
Formula or method
Cells store typed data and formulas. Basic arithmetic and SUM, AVERAGE, MIN, MAX and COUNT formulas are evaluated locally; XLSX files are loaded and saved in your browser.
Worked example
Paste a sales table, enter =B2*C2 to calculate a line total, then use =SUM(D2:D10) to sum amounts.
How to use the tool
- Open an XLSX, CSV or TSV file, or enter data into the sheet.
- Edit cells and try arithmetic, SUM or AVERAGE; use separate sheets for small tables.
- Export XLSX/CSV and reopen the file to confirm data types, formulas and leading zeros.
Common uses
Everyday documents, school and office tasks, productivity and file conversion.
When this tool is useful
Edit a small spreadsheet, check basic formulas and export XLSX or CSV without a subscription.
What to check before relying on the result
This lightweight editor has size limits and does not preserve macros, charts, pivot tables or advanced formula behavior.
Assumptions and limitations
Limited to five sheets, 200 rows and 26 columns each. Imported formatting, macros, pivot tables, charts and advanced formulas may not work. Download before closing.
Frequently asked questions
Can I open and edit an Excel spreadsheet online?
Yes, for basic XLSX/CSV tables, values and simple formulas. Complex workbooks are not supported.
Will my original Excel charts and formatting survive export?
No. The editor focuses on values and basic formulas, so inspect the exported workbook before using it for reporting.
Continue with a related workflow
Privacy and support
Your inputs are processed locally in your browser. ToolMosaic does not upload or store the values you enter in this tool. Our tools are free, and we appreciate your support.