About Spreadsheet Editor
Spreadsheet Editor is a browser-based spreadsheet for everyday calculations — budgets, expense logs, simple data analysis, classroom gradesheets. It includes a custom formula engine with the common functions (SUM, AVERAGE, IF, VLOOKUP, COUNTIF and many more), multi-sheet workbooks, cell formatting, sorting, freeze panes and embedded charts. Import .xlsx and .csv via SheetJS, export to either format. Every change autosaves to IndexedDB. It isn't a full Excel clone — there's no pivot table or macros — but it handles real spreadsheets you'd otherwise need a desktop app for.
- No uploads
- Browser-only
- Works offline
- 100% free
How it works
- 1
Open or start a workbook
Start from blank, or drop an .xlsx or .csv. Multiple sheets are loaded with their formatting and formulas preserved as far as the engine supports them.
- 2
Type, format, formula
Click into a cell and type — text, numbers, or =FORMULA(...). The formula bar shows the source; keyboard navigation (arrows, Enter, Tab, Ctrl+arrows) works like any spreadsheet.
- 3
Export back to .xlsx or .csv
When you're done, export to .xlsx (preserves multi-sheet, formatting, formulas) or .csv (single sheet, values only). Autosave keeps the workbook in your browser between sessions.
A spreadsheet that opens in a tab and stays on your machine
The everyday case isn't building a financial model — it's opening the .xlsx someone emailed you, changing three cells, and sending it back. On a machine without Excel, that ordinarily means uploading a file with your company's numbers in it to a website you'd never heard of ten seconds earlier.
This runs entirely in the browser. Cells, formulas, multi-sheet workbooks, formatting, sorting and the keyboard shortcuts your hands already know — with .xlsx and .csv in and out. The file never leaves the tab, so there's no upload to regret.
Formulas, and the honest limits of them
The common functions are here: arithmetic, SUM, AVERAGE, COUNT, MIN and MAX, IF, and cell and range references across sheets. That covers the great majority of what spreadsheets actually contain, which is arithmetic with labels on it.
It is not Excel's formula engine. There is no VLOOKUP-and-friends parity, no array formulas, no pivot tables, no macros. A workbook whose logic lives in those will open and show its values, but the formulas behind them won't recalculate here. If your workbook is a model rather than a table, use Excel.
What survives a round trip
- Values, formulas, and multiple sheets with their names.
- Number formats — currency, percentages, dates — read from the workbook's own style definitions rather than guessed from the value.
- Fonts, sizes, bold/italic, text and fill colours, column widths and merged cells.
- Not kept: charts, images, conditional formatting rules, data validation, pivot tables and macros. These are separate parts of the file that this doesn't read or write.
CSV is a different animal, and it bites
A CSV has no types, no formatting and no sheets — it's text with commas. Every spreadsheet program guesses what the text means when it opens one, and the guesses are where data dies: a product code like `007` loses its zeros, `1-2` becomes a date, and a long number becomes scientific notation. Those conversions are silent and permanent once saved.
The practical rule: use .xlsx when the file matters, CSV when you're moving data between systems that both agree on what it means. If you're converting between structured formats, CSV to JSON keeps the values as strings and doesn't guess at all.
Related guides
All guidesFrequently asked questions about Spreadsheet Editor
Which formulas are supported?
Most of the everyday set — SUM, AVERAGE, MIN, MAX, COUNT, COUNTIF, SUMIF, IF, IFS, AND, OR, NOT, ROUND, ABS, VLOOKUP, INDEX, MATCH, TEXT, CONCAT, LEN, LEFT, RIGHT, MID, TODAY, NOW, plus arithmetic and comparison operators. Niche or very recent additions (LAMBDA, dynamic arrays, RAND with seed) are not supported.
Is this an Excel replacement?
For everyday spreadsheets — household budgets, expense tracking, simple reports, gradesheets — yes. For heavy analytic workflows (pivot tables, Power Query, VBA macros, conditional formatting on complex rules, large datasets above ~50,000 cells) you'll want Excel or Google Sheets. The .xlsx round-trip means you can hand off the file in either direction.
How accurate is the .xlsx import?
SheetJS handles the heavy lifting — values, formulas, basic formatting, multi-sheet structure, freeze panes and embedded charts round-trip well. Conditional formatting, pivot tables, macros, custom number formats and chart styling are simplified or dropped. For a quick view or light edit, fidelity is high; for complex workbooks, open in Excel.
Privacy, offline use, browser support, and pricing questions are answered on the site-wide FAQ.