Why does my exported CSV open correctly in Excel?

Excel often reads CSV files without a byte-order mark using a legacy code page, which garbles non-English text. By default the CSV export starts with a UTF-8 BOM so Excel detects the encoding; untick the option if a program needs plain UTF-8. On import, the tool first tries strict UTF-8 and falls back to GBK, so Chinese CSVs saved by Excel also display correctly.

Which formulas are supported? Is it the same as Excel?

You get + - * / ^, percent, & for joining text, comparisons (= <> =), cell references (A1, $A$1) and ranges (A1:B10). Functions include SUM, AVERAGE, MIN, MAX, COUNT, COUNTA, IF, IFERROR, AND, OR, NOT, ROUND, ROUNDUP, ROUNDDOWN, INT, ABS, SQRT, POWER, MOD, LEN, UPPER, LOWER, TRIM and CONCAT. It’s a lightweight sheet: no VLOOKUP, date functions, multiple sheets, charts or merged cells.

How big can a sheet be?

Only the rows on screen are rendered, so tens of thousands of rows scroll and edit smoothly; the limit is about 200,000 rows and 256 columns. Autosave uses your browser’s local storage (usually around 5 MB), so very large sheets may be too big to autosave — the tool tells you when that happens, and you should export a copy.

Is my data uploaded? Will it still be there tomorrow?

Nothing is uploaded: editing, formula calculation, import and export all run in your browser. The sheet autosaves to local storage, so it survives closing the tab, but clearing browser data or switching devices loses it — export CSV or JSON for anything important.

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▦Online Spreadsheet - Free CSV Editor with Formulas

A lightweight spreadsheet that opens instantly in your browser — handy for tidying data, editing CSV files, or keeping a quick budget or grade sheet. Move with the arrow keys, press Enter or double-click to edit, Tab to move right and Shift + arrows to select a range; Ctrl/⌘ + C and V copy and paste straight to and from Excel, Google Sheets or Numbers. Start a cell with = to write a formula: arithmetic, powers, percentages, text joining and comparisons, plus SUM, AVERAGE, MIN, MAX, COUNT, IF, ROUND, IFERROR and more. When you change a cell, every formula that depends on it recalculates, and circular references show #CIRC!. Insert, delete and move rows and columns (formula references follow along), sort by a column, filter with conditions such as >100, find and replace, and format columns as numbers with thousands separators, percentages, currency or dates. The first row can act as a frozen header, and virtual scrolling keeps tens of thousands of rows smooth. Imports detect UTF-8 or GBK automatically, and exports include CSV (optionally with a BOM for Excel), TSV, JSON and Markdown tables. Everything autosaves in your browser and is never uploaded.

Free · No sign-up · Runs in your browserLast updated: 2026-10-26

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How to use Online Spreadsheet

1Type into the grid, click Import to open a CSV, TSV or JSON file, or paste cells copied from Excel
2Enter formulas starting with =, then insert or delete rows and columns, sort, filter, find and replace, and set column formats
3Export as CSV, TSV, JSON or a Markdown table

FAQ

Why does my exported CSV open correctly in Excel?: Excel often reads CSV files without a byte-order mark using a legacy code page, which garbles non-English text. By default the CSV export starts with a UTF-8 BOM so Excel detects the encoding; untick the option if a program needs plain UTF-8. On import, the tool first tries strict UTF-8 and falls back to GBK, so Chinese CSVs saved by Excel also display correctly.
Which formulas are supported? Is it the same as Excel?: You get + - * / ^, percent, & for joining text, comparisons (= <> < > <= >=), cell references (A1, $A$1) and ranges (A1:B10). Functions include SUM, AVERAGE, MIN, MAX, COUNT, COUNTA, IF, IFERROR, AND, OR, NOT, ROUND, ROUNDUP, ROUNDDOWN, INT, ABS, SQRT, POWER, MOD, LEN, UPPER, LOWER, TRIM and CONCAT. It’s a lightweight sheet: no VLOOKUP, date functions, multiple sheets, charts or merged cells.
How big can a sheet be?: Only the rows on screen are rendered, so tens of thousands of rows scroll and edit smoothly; the limit is about 200,000 rows and 256 columns. Autosave uses your browser’s local storage (usually around 5 MB), so very large sheets may be too big to autosave — the tool tells you when that happens, and you should export a copy.
Is my data uploaded? Will it still be there tomorrow?: Nothing is uploaded: editing, formula calculation, import and export all run in your browser. The sheet autosaves to local storage, so it survives closing the tab, but clearing browser data or switching devices loses it — export CSV or JSON for anything important.