For two years the AI-and-spreadsheets workflow was copy, paste, describe, paste back. That gap has closed. OpenAI ships an add-on that puts ChatGPT in a sidebar inside both Excel and Google Sheets, and Google has Gemini built into Sheets natively. The assistant now reads the actual cells and writes into them.
Which means the interesting question is no longer whether to use AI on your spreadsheets. It's which sidebar, and where you still need to keep your hands on the wheel.
What both do well
Writing and explaining formulas is where the value shows up fastest. Describe what you want in plain language and get a working formula, or paste in an inherited nightmare of nested lookups and get an explanation of what it does. Both handle cleanup competently — splitting name columns, standardizing dates, flagging inconsistent entries. Both can summarize a range and suggest a chart.
If your honest use case is "I want to stop googling formula syntax and stop hand-fixing messy exports," either one will do that, today.
Where they differ, practically
The real split is data gravity. Google's assistant lives inside your Workspace account, so it reaches your Drive context without you moving anything, and there's no separate subscription to reason about. OpenAI's add-on is cross-suite — the same assistant in Excel and in Sheets — which matters if your accountant sends xlsx and your team lives in Sheets, or if you already pay for ChatGPT and want that one assistant everywhere.
Neither is meaningfully smarter than the other at the work an SMB actually does in a spreadsheet. Pick on plumbing, not on benchmarks.
The part everyone underestimates
These assistants are confident on structure and shaky on judgment. They will happily build a forecast from a column without knowing that three of those months included a one-time contract. They cannot tell that a customer got renamed halfway through the year. Multi-tab workbooks with cross-sheet references are where errors hide, because the mistake shows up two tabs away from where it was made.
Treat generated formulas the way you'd treat work from a fast new hire: check the output against a number you already know before you trust the rest.
The caveat on availability and price
Access tiers and usage limits for both products have moved several times this year, and free-preview windows for business plans have been expiring. Before you standardize your team on one, confirm what your current plan actually includes rather than what it included when you signed up.
The takeaway
Default to whichever suite your data already lives in — that's the right answer for most small businesses and it costs you almost nothing to be wrong about. Run one real workbook through it this week, verify two known numbers by hand, and decide from there.