Use an AI assistant beside Excel, without leaving the spreadsheet

A quick question, and the trip around it

The usual version goes like this. A lookup on row 214 returns #N/A. You switch to the browser, find the tab with the AI in it, paste the formula, then describe in words what the data looks like, because the tab cannot see your sheet. You read the answer, copy the corrected formula, switch back to Excel, find row 214 again and paste.

None of that is difficult, and none of it is the question. It is navigation, and it happens every time. The practical result is that small questions stop getting asked, and the formula gets worked out the slow way, which is exactly where a quick answer would have helped most.

Beside Excel, not inside it

SideNote Pro is a separate Windows application. While you work it waits as a small leash on the right edge of the display. Press Ctrl+Shift+Space in Excel, or click the leash, and the assistant opens on that edge with the sheet still visible beside it. Esc retracts it again, and the conversation stays where it was for the next question. The Windows AI sidebar page covers the drawer, multiple monitors and startup in detail.

The panel sits over the right-hand side of the screen rather than resizing Excel. If the columns you need are on that side, window transparency, from 0 to 50 percent in Settings, Appearance, keeps them readable behind it. Or switch the drawer off in Settings, General and let the window float wherever suits the sheet.

Where it earns its place in a spreadsheet

Explaining a formula you inherited

A nested IF, or an INDEX and MATCH pair written by someone who has since moved on. Select it in the formula bar and press Explain.

Troubleshooting an error value

#N/A, #VALUE!, #SPILL!. The formula alone is rarely enough, so add a sentence about the data it runs on. There is a worked example below.

Writing a formula you can describe but not spell

Total column C where column B falls in March and column D says Paid is a plain sentence to type with the sheet in view, and the formula that comes back goes into the formula bar with one paste.

Cleaning up text in cells

Company names spelled four ways, addresses in five formats, free-text notes. Select the cells, ask for a table with the columns you want, and paste it back.

Summarizing or translating what cells say

A column of survey comments through Summarize, or product descriptions through Translate.

Reading a chart or pivot table you did not build

Capture that region of the screen and ask what it shows. This needs a model that accepts images.

What a selection sends from Excel

Selected-text shortcuts work in Excel the way they do in any application. SideNote Pro sends Ctrl+C to Excel, reads the text Excel puts on the clipboard, and then restores whatever you had copied before. What matters in a spreadsheet is what that text is.

So to ask about a formula, select the formula, not the cell. And when you send a range, the model sees the numbers, not how they were calculated.

Which shortcut you press decides when the text is sent. Ask SideNote, Ctrl+Shift+A by default, captures the selection and waits for your question, which is usually what a spreadsheet needs, because the formula alone rarely says what is wrong. Explain, Summarize, Rewrite and Translate send the moment you press them. With a range that holds anything sensitive, that difference is worth remembering. Each shortcut also starts a new conversation with the selection in it, so follow-up questions go in that conversation's message box.

Pasting is different from a selection shortcut. If the clipboard contains an image, Ctrl+V in SideNote Pro attaches it, and Excel can also copy a selected cell range as a picture. When you want the values as text, a selection shortcut is the reliable route. And if Excel is running as administrator while SideNote Pro is not, Windows blocks the copy: nothing is sent, and the assistant tells you so.

An Explain action that knows your Excel

The built-in Explain does not know which Excel you have, and it matters. XLOOKUP and FILTER exist in Excel for Microsoft 365 and Excel 2021 or later, not in Excel 2016 or 2019, and in many European locales Excel separates arguments with semicolons and uses translated function names. A custom action can carry that context every time:

Explain what this Excel formula does, step by step,
then list what would make it return an error.
I use Excel for Microsoft 365, with English function
names and commas between arguments.

{{selection}}

Give it a shortcut of its own and it becomes the one you reach for in a spreadsheet. If you would rather state your Excel version once for everything, put it in your default profile under Settings, System prompt, which is sent with every request.

Worked example: a lookup that returns #N/A

A price lookup works for most rows and returns #N/A for about a third of them, although the product codes look identical on both sheets.

=VLOOKUP(A2,Prices!A:C,3,FALSE)

1. Select the formula, not the cellClick a cell showing #N/A, then select the formula text in the formula bar.
2. Press Ask SideNoteCtrl+Shift+A by default. The assistant opens on the right edge with the formula captured, and the sheet stays where it is.
3. Say what the formula cannotThe model sees the formula, not your data. Something like This returns #N/A for about a third of the rows, but the codes look the same on both sheets. What should I check first?
4. Check the answer against the sheetA useful answer names the usual causes of exactly this symptom, such as stray spaces, codes stored as text on one sheet and as numbers on the other, or lost leading zeros, and says how to tell them apart: comparing =LEN(A2) with the length of the code you can see, for instance.
5. Paste the fix and carry onWhen the answer gives a corrected formula in a code block, the block's copy button copies it exactly. Press Esc to retract the panel and paste it into the formula bar.

If the answer stays generic, show it the data. In the same conversation, capture both columns of codes with the screenshot tool and ask again. A picture often shows what a description leaves out, such as codes aligned left on one sheet, where Excel is treating them as text, and right on the other, where they are numbers.

Treat the answer as a lead to check, not a verdict. A model can be confidently wrong about a formula, and the sheet is where you find out.

Getting answers back into the sheet

A formula

When the answer puts it in a code block, the block's copy button copies it exactly as written. Paste it into the formula bar.

A table

Copy table, in the top-right corner of any table in an answer, copies it with its header row, so pasting into Excel lands in proper rows and columns. Every cell arrives as text, exactly as the answer showed it: 007 stays 007 and =1+1 stays as written rather than being calculated. That protects codes and IDs, but a column of figures you want to calculate with needs converting to numbers after the paste.

Prose

Select the part of the answer you want and copy it, or copy the whole response with its copy action.

Two Excel shortcuts the defaults take over

SideNote Pro's shortcuts are registered with Windows, so while it is running they work in every application and replace the same keys inside Excel. Two of the defaults are also Excel shortcuts, as Microsoft's list of Excel keyboard shortcuts shows:

If you rely on either, change the summon shortcut in Settings, Keyboard and the action shortcut in Settings, Actions and prompts, where an empty box leaves that action unassigned. Pausing global shortcuts from the tray icon hands every key back to Excel until you resume them.

How this differs from an AI add-in for Excel

An assistant built into Excel, or installed as an add-in, works inside the workbook, so it can be given the sheet itself to read and, depending on the product, to change. If that is what you want, an add-in is the right kind of tool, and SideNote Pro is not a substitute for one.

SideNote Pro works from outside. It sees only what you hand it, and it changes nothing unless you paste. What you get in return:

One assistant beside everything

The same shortcuts and the same local history beside Excel, Word, the browser and the PDF reader, rather than a separate assistant in each.

Your own provider and model

SideNote Pro connects to the AI provider you configure with your own API key, or to a local model, and the provider bills its usage directly. A formula question rarely needs a large model, so a profile on a fast, low-cost one keeps those questions cheap. A model for each kind of task covers the split.

Nothing installed in Excel

There is no add-in to deploy, and nothing in the workbook changes when you ask a question.

Whatever you select or capture goes to the provider your active profile points at, when the request is sent, and to nothing else. For a sheet that should not reach a hosted provider at all, such as payroll or client data under restriction, switch to a local model profile before you select anything.