How to Smart-Fill a Column in Excel with AI (Extract by Instruction)
Flash Fill can split a column when there's a clean pattern to copy — but ask it to "extract the brand" from a messy product description and it falls apart. Here's the AI way: describe the result you want in plain English, and a new column fills itself from your source column, using your own AI key.
Last updated: August 2026
| Description | Brand (new column) | |
|---|---|---|
| Apple iPhone 14 128GB | → | Apple |
| Galaxy S23 Ultra by Samsung | → | Samsung |
| Sony WH-1000XM5 | → | Sony |
Why Excel makes this hard
Flash Fill and Split by Example only learn a positional pattern from the example rows you type — take the text before the space, grab the last four characters, and so on. That's perfect for splitting John Smith into first and last, but it breaks the moment the task is semantic. There's no fixed pattern for "extract the brand" when the brand sits at the front of one description and the end of another. So people fall back to pasting each cell into ChatGPT and copying the answer back — manual, slow, and it hands your business data to a third-party chat window.
The 1-click way — Tellsheet's AI Smart Fill
Select the source column and run AI Smart Fill. Type a plain-English instruction — "extract the brand", "pull the invoice number", "Title-Case the city" — and it fills a new column beside the source using your own Anthropic API key. Only the selected text is sent, there's no Tellsheet backend, and nothing is stored; blank cells pass through untouched. No example rows to set up — the AI sibling of Flash Fill. Pairs with Split by Example and Extract Text from a Cell.
Frequently asked questions
How is this different from Flash Fill?
Flash Fill copies a pattern from example rows and breaks on anything semantic. AI Smart Fill takes a plain-English instruction instead — no examples needed.
Where does my data go?
Only the selected text, only to Anthropic under your own key. No backend, nothing stored.
Does it overwrite my column?
No — the result lands in a new column beside the source, so the original stays.
What about blank cells?
They're passed through unchanged — only real text is processed.
Related Excel guides
Fill a column by describing it
AI Smart Fill turns a plain-English instruction into a new column — no example rows, your own AI key, only the text is sent.
Get Tellsheet free See pricing