A spreadsheet you can ask to do the work
Kantaja is a spreadsheet editor in the browser. Open an .xlsx, describe the change in your own words, and the edits land in the grid, ready to check and export.
- Opens and saves .xlsx
- Edits happen in the grid, not in chat
- Free plan, no card
One run, start to finish
Import your workbook
Upload an .xlsx, or start from an empty sheet. It runs in the browser, so there is nothing to install.
Describe the change
"Fill the unit price column from the price list PDF." Attach the documents the answers come from, and the assistant searches them before it writes.
Check it and export
Each action shows the range it touched, so you can spot-check the cells. Fix anything by hand, revert the run, or export the .xlsx.
30-second tour
Watch one request become a budget
A plain-English request turns into a monthly budget with formulas, currency formatting and a chart, with each change listed as it lands in the sheet.
Read what the video shows
- What are we building? Describe the spreadsheet and the assistant builds it in the sheet.
- The request typed in: "Build a monthly budget with income, expenses and a savings rate."
- Describe it. The assistant builds it in the sheet. Headers, income rows and expense rows appear in the grid.
- A real workbook, with real formulas. Totals, savings and the savings rate are calculated from the cells above.
- Every edit is logged and undoable. The assistant lists six changes: column headers, income rows, expense rows, totals and formulas, currency formatting and a chart.
- Round-trip your .xlsx files. Values, formulas, formatting and layout carry over.
- Kantaja. Describe the spreadsheet. Kantaja builds it.
Knowledge base
Attach the documents the answers come from
Prices in a supplier PDF, terms in a contract, notes in a text file. Kantaja indexes what you attach and searches it when a request depends on it, then writes the values it found into the cells. Every search is logged with the query it ran, so you can see when an answer drew on your documents.
- PDF, Word and plain text, up to 20 files per workbook
- Every search shows in the action log with its query
- Available in chat and inside =AI() formulas
Attached files are stored in your account and you can delete them at any time. See the privacy notice.
The =AI() formula
AI in a cell, like any formula
Give it a prompt and the cells to look at, then fill it down. One value per row: categorize expenses, translate a column, pull a number out of a messy text field. A result holds until its inputs change or you refresh it, so editing elsewhere in the sheet does not recalculate and re-bill the column.
- Fill down a column like any other formula
- A result holds until its inputs change or you refresh it
- Can search your attached documents for the answer
Examples
Requests that take one line
"Add a margin column next to revenue and format it as a percentage"
"Fill the unit price column from the price list I attached"
"Categorize each expense as travel, software, meals or marketing"
Mistakes are visible and easy to undo
It's a language model, so it will sometimes misread a request or a column. Kantaja is built so you catch that early: only three actions can write to your sheet, and each one is logged with the exact range it touched while it runs.
Revert a run
A run is one entry in the log, and reverting undoes exactly what it wrote. If you have edited the sheet since the run finished, Kantaja refuses to revert over your changes and points you to normal undo instead.
Can write to your sheet
Read-only
Questions, answered
What happens to my files and my data?
Workbooks and attached documents are stored in your account, and you can delete them at any time. Prompts and the data they reference are processed by AI model providers to produce the result, and cached =AI() results expire after about 60 days. See the privacy notice for the full detail.
How faithful is the .xlsx round trip?
Values, formulas, number formats and multiple sheets survive import and export. Very Excel-specific features such as pivot tables, macros and charts are not supported, so check a copy before you replace an original. See the full compatibility matrix.
What if it does the wrong thing?
Each action shows the range it touched while it runs, so you can check the cells straight away. You can edit anything by hand, or revert a whole run in one click. What revert restores, and known failure modes.
Do I need Excel installed?
No. Kantaja is a spreadsheet editor that runs in the browser. You only need Excel for whatever you do with the file afterwards. More on the online Excel editor.
What documents can it read?
PDF, Word and plain text, up to 20 files per workbook. The assistant and =AI() search them when a request depends on them, and every search appears in the action log with the query it ran.
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.
Can my team work in the same workbooks?
Yes, on the Business plan. Create an organization and invite members; its workbooks are shared between them. It is not live co-editing: you open the latest saved version rather than seeing each other type.