Ask questions about your data in Microsoft Excel.

See how the answer is calculated, step by step.

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Compare to Copilot
Excel answer with highlighted source rows and visible query
Why us

The answer comes with the query that produced it

The number, and the query that made it

Each answer arrives with the query it ran on your sheet. Open the query to verify the filter, calculation and source rows.

The number, and the query that made it
It tells you when your sheet falls short

It tells you when your sheet falls short

When your data cannot answer the question, it asks you to clarify instead of returning a figure.

Never writes into your data

Your workbook is uploaded and read, never altered. Derived columns and lookups appear separately.

Never writes into your data
The values that need a source

The values that need a source

Dated facts such as exchange rates are looked up from public sources like the ECB. The source is shown with the answer.

Head to head

Prereasoner vs Microsoft 365 Copilot

Copilot works inside Excel. Prereasoner works on an uploaded copy and shows the query behind each answer.

On your spreadsheetMicrosoft 365 CopilotCopilot for Microsoft Excel by Prereasoner
Where it runsInside ExcelIn the browser, on an uploaded workbook
Shows the query and source rowsFor supported questionsWith each answer
Self-hostingNot availableOpen source Community Edition
How it works

Four steps from question to auditable number

01 UPLOAD

Your workbook

Upload your Excel file. Your data is read, never changed.

02 UNDERSTAND

It reads your columns

Prereasoner works out what each column holds, such as places, amounts or dates.

03 CALCULATE

One exact calculation

Your question becomes one exact calculation on your data.

04 SHOW

Answer with its query

The answer appears with the calculation behind it and any sources it looked up.

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Copilot for Excel that looks it up instead of making it up

Upload an .xlsx and get the result with its query and source rows.

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