AI extensions for Excel and what each one actually does

“AI for Excel” covers three different products that get sold as one thing. The useful question is not which is best, it is which of the three shapes matches the work in front of you.

• A sidebar assistant sits beside the grid, reads the open workbook, and answers questions about it. Good for understanding and repairing a file you did not build.
• A worksheet function puts a model inside a cell, so a prompt runs down a column. Good for a thousand rows of text that need the same treatment.
• A formula generator turns a sentence into a formula, usually in a browser. Good when you know what you want and cannot remember the syntax.

Everything below was checked against the vendor’s own documentation in July 2026. Prices and free tiers move; capabilities move slower.

Sidebar assistants

Claude for Excel

Anthropic’s add-in runs in a side panel and works on the workbook you have open. What separates it from a chat window you paste into: it answers with cell-level citations, so you can see which cells an answer came from, and it changes assumptions without breaking the formula dependencies that already exist. It traces an error to its root cause rather than only reporting it, navigates multi-tab models, builds new models or fills templates, and applies ordinary Excel operations like sorting and conditional formatting.

Available on Claude’s Pro, Max, Team and Enterprise plans, for Excel on the web, on Windows, on Mac and on iPad. You install it from the Microsoft Marketplace listing for Claude for Microsoft 365, then sign in from inside Excel.

Copilot in Excel

Microsoft’s own, and the one already inside the application for many people. It edits worksheets, writes formulas, creates charts and PivotTables, points out patterns in a range, filters and sorts, searches the web, and imports from other workbooks.

Two things to check before you plan around it. Microsoft states plainly that Copilot might not be included in your Microsoft 365 subscription, and that an organisation can switch it off. Check your own licence in the Microsoft 365 admin centre rather than assuming, because “Excel has AI now” is true of the product and not necessarily of your install.

Worksheet functions

This is the shape people underuse. Instead of a conversation, you get a function that fills down like any other.

• GPT for Excel adds =GPT(). Write the prompt once, fill it down a column, and a thousand rows of survey responses or product names get the same treatment. It works against OpenAI, Claude or Azure endpoints, and you can supply your own key.
• Numerous.ai adds =AI() with the same idea and a narrower focus: classifying, summarising, and normalising inconsistent text in place.
• Excel Labs adds LABS.GENERATIVEAI(). This is a Microsoft Garage experiment, explicitly not Copilot, and it requires your own OpenAI API key — which is the honest version of AI pricing, since you see the cost of each call. The same add-in carries the Advanced Formula Environment for writing and reusing named LAMBDA functions.

A worksheet function that calls a model recalculates like a formula but costs money and time every time it does. Convert the results to static values with Paste Special once you are happy with them, or a stray recalculation will bill you twice for the same answer.

Formula generators

• Formula Bot — plain English to formula, and beyond that a data-prep tool: PDF and bank statement conversion into structured sheets, and a formatted spreadsheet built from a description.
• Ajelix — the strongest of these on VBA, which the sidebar assistants handle poorly. It generates, debugs, optimises and explains macro code. It also translates formulas between Excel’s localised function names, which is a real problem for anyone working across language versions and one almost nothing else solves.
• GPTExcel — web only, no add-in, which matters if your employer will not let you install one. Returns formulas, SQL, regex and Apps Script across Excel, Google Sheets, LibreOffice Calc and Airtable.

Google Sheets, briefly

If part of your work lives in Sheets, Gemini is its built-in equivalent, opened from Ask Gemini at the top right. It builds tables and charts, writes formulas, adds pivot tables and conditional formatting, and can pull context from Gmail and Drive — which Excel has no equivalent for. It needs an eligible Google Workspace or Google AI plan.

What to check before you trust any of it

The failure mode is not a wrong answer that looks wrong. It is a plausible formula that is subtly wrong on the edges.

1. Check the ranges, not the result. A formula that returns a believable number from the wrong range is the expensive mistake. Read the references.
2. Test one row you already know the answer to. If it cannot reproduce a figure you have verified by hand, nothing further it says is worth reading.
3. Ask what happens when the input is empty, text, negative, or zero. Most generated formulas are correct for the happy path and silent about the rest.
4. Watch for the volatile function trap. A generated formula built on TODAY() or NOW() will change its answer tomorrow.

Before you paste anything

Every tool here sends your data somewhere. That is the deal, and it is fine for a product list; it is not automatically fine for payroll, patient records, unreleased results or anything under an NDA.

Two rules that keep this simple. Do not paste confidential data into a tool your organisation has not approved for it, whoever built the tool. And prefer the option where the data goes somewhere you already have an agreement with — for most companies that means the assistant inside the tenant they already pay for, rather than the free web app with the better formula output.

For links to everything named here, see the AI tools and add-ins for Excel section of the directory. For prompt wording, see Excel Copilot prompt ideas.