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Online Excel editor

Edit Excel files online, free

Open your .xlsx in a real grid, change values, formulas and formatting, then export the file. Nothing to install, and an AI assistant when you would rather describe the change.

  • Opens and saves .xlsx
  • Formulas and number formats survive
  • Free plan, no card
Static example of the editor. An imported .xlsx opens as real cells: a formula bar, currency number formats and the workbook's sheets, with export writing the same file back.

What the editor includes

A real grid

Click into cells and type, select ranges, and work across multiple sheets in one workbook.

Formulas

Write formulas in the formula bar; they recalculate as the sheet changes.

Formatting

Number formats and cell styling from the toolbar.

Import and export .xlsx

Open a file from your computer and export the edited workbook as .xlsx.

What survives the round trip

Values, formulas, number formats and multiple sheets survive import and export. Pivot tables and macros are not supported, charts in an imported file are not kept, and charts made in Kantaja export as pictures rather than live Excel charts, so check a copy before you replace an original. See the full compatibility matrix.

You can also ask for the edit

Describe a change in your own words and the assistant makes the edits in the grid: each action is logged with the exact range it touched, and a whole run can be reverted in one click. Attach the documents the answers come from, and it searches them before it writes.

Questions about the editor

Is it free to edit Excel files online here?

Yes. The free plan includes the full editor, .xlsx import and export and 5 saved workbooks, with 4 AI credits a day and no card. Paid plans change the AI budget and lift the workbook limit. Compare plans.

Do I need Excel or Microsoft 365 installed?

No. Kantaja runs in the browser. You only need Excel for whatever you do with the file afterwards.

Can I open .xls or .csv files?

Workbooks open as .xlsx or .xlsm and export as .xlsx. For an older .xls file, save it as .xlsx in Excel or another tool first. A .csv does not open in the grid directly: attach it as a document and ask the assistant to bring its rows into the sheet, or save it as .xlsx first.

What is =AI()?

A worksheet function: give it a prompt and the cells to look at, and it returns one value per cell. Fill it down like any formula. A result stays put until its inputs change or you refresh it, so it is not recalculated and re-billed on every edit.

What happens when the AI credits run out?

AI features pause until the budget resets: the next day on the free plan, the first of the next month on paid plans. The editor keeps working, so you can carry on by hand or upgrade for a bigger budget.

Try it on a file you already have

Start freeFree plan: 4 AI credits a day, 5 workbooks, no card.