What can it do?
- Write a formula from a description: “sum column C where column A is Rent and the date in B is in March”, “find the price for this SKU in the Products table”, “rank the scores in D without gaps”. You get the formula, the cell it belongs in and a short explanation.
- Use your own columns. Attach the workbook and the formula uses your real sheet names, ranges and table columns instead of placeholders.
- Summarize a workbook: what each sheet holds, the main totals and trends, anything unusual, with cell references.
- Explain formulas someone else wrote, in plain language.
- Check for mistakes: totals that skip rows, numbers typed over formulas, a formula that changes halfway down a column, error values.
- Suggest charts or a PivotTable for your data, with the range to select.
- Make or clean up a table: sample data, a schedule, a budget template, or your messy column of dates turned into a tidy table that opens in GridCraft.
How do the results get into the spreadsheet?
GridCraft’s web build is used as released, so the panel works through the doors the app already has:
- Formulas appear with a Copy button. Click a cell in GridCraft and press Ctrl/⌘+V: pasted text that starts with
=is entered as a formula. - Tables appear as a preview with Open in GridCraft, which hands the table to the app as a CSV file, exactly like dropping one on the grid; it opens as a new workbook. Copy for pasting puts it on the clipboard as tab-separated text, so you can paste it at the selected cell of a sheet you already have. You can also download it as
.csv. - Your workbook reaches the panel when you save: GridCraft’s Save downloads the .xlsx as usual, and the page keeps a copy for the panel. You can also upload an .xlsx or .csv file, or drop one on the panel.
Step by step
- In the editor, click Spreadsheet AI in the top bar. The panel opens on the right and the grid resizes to fit.
- Open the settings (gear icon), choose a provider and paste your API key. The key field links to the provider’s key page.
- For a formula or a table, just type what you need, or pick Write a formula or Make a table and finish the sentence.
- To ask about your data, save in GridCraft first (Save button or Ctrl/⌘+S). The workbook appears in the panel; leave “Send this workbook with my questions” ticked.
- Press Ask (or Ctrl/⌘+Enter). Ask follow-up questions in the same conversation; the last few exchanges are sent along.
Formulas that work in GridCraft
GridCraft has 501 of Excel’s 523 worksheet functions, including dynamic arrays (FILTER, SORT, UNIQUE, XLOOKUP), LET and LAMBDA. The panel tells the model which ones are missing or only return an error in GridCraft, so it reaches for something else:
FORECAST.ETS, FORECAST.ETS.CONFINT, FORECAST.ETS.SEASONALITY, FORECAST.ETS.STAT, PERCENTOF, ODDFPRICE, ODDFYIELD, ODDLPRICE, ODDLYIELD, BAHTTEXT, DETECTLANGUAGE, TRANSLATE, GETPIVOTDATA, IMAGE, RTD, TRIMRANGE, STOCKHISTORY, CALL, EUROCONVERT, REGISTER.ID, COPILOT, PY, CUBEKPIMEMBER, CUBEMEMBER, CUBEMEMBERPROPERTY, CUBERANKEDMEMBER, CUBESET, CUBESETCOUNT, CUBEVALUE, WEBSERVICE, FILTERXML
Formulas are written with English function names and commas between arguments, which is what GridCraft stores and what pasting expects. If your browser is set to Spanish, GridCraft shows Spanish function names in the formula bar (SUMA, SI, BUSCARV), but pasted English formulas still work.
Supported providers
| Provider | Default model | Get a key |
|---|---|---|
| OpenAI | gpt-6.1-sol | platform.openai.com |
| Google Gemini | gemini-3.8-flash | aistudio.google.com |
| OpenRouter | google/gemini-3.8-flash | openrouter.ai |
| Custom (OpenAI-compatible) | any model your API serves | your own endpoint |
Workbooks are sent as text, so any text model works: OpenAI through its Responses API, Gemini through generateContent, and OpenRouter’s models from OpenAI, Google, Anthropic, DeepSeek, xAI and others. The custom option works with any service that implements OpenAI-style /chat/completions and accepts browser requests. Load models in the settings lists what your key can use.
Privacy: what goes where
| Data | Where it goes |
|---|---|
| Your API key | Stays in your browser. Sent only to the provider, in the request header. |
| Your questions | Sent from your browser straight to the provider you chose. OpenAI requests ask it not to store the response. |
| Your workbook | Converted to text in your browser and sent to the provider only when it is attached to a question. |
| Everything else you do in GridCraft | Never leaves your device. |
| gridcraft.run servers | Serve the static app files. They receive none of the above. |
The provider’s own terms and data policy apply to what you send them. For confidential data, untick “Send this workbook” and describe your columns in words instead, or save a copy with only the rows the model needs.
FAQ
Is the AI formula generator free?
gridcraft.run charges nothing and adds no markup, because requests never pass through us. You pay your AI provider for what you use at their normal API prices. A formula question is a few hundred tokens, a fraction of a cent with a fast model; questions with a large workbook attached cost more, because the workbook is sent each time.
Where is my API key stored?
In your browser only. By default it lasts for the current tab (sessionStorage). Tick “Remember my key on this device” to keep it in localStorage instead, and use “Forget all keys” in the panel settings to delete it.
Do the formulas work in Excel and Google Sheets too?
Usually, yes. The panel asks for standard Excel formulas with English function names and comma separators, which Excel uses and Google Sheets reads for most functions. Newer functions such as LET, LAMBDA or XLOOKUP need Microsoft 365 or Excel 2021 or later. Test a formula on a few rows before you rely on it.
What does the model see when I attach a workbook?
A text version made in your browser: each sheet’s cell values in a grid with column letters and row numbers, its formulas by cell, and the names of tables and defined names. Formatting, charts and pictures are not sent. Very large sheets are cut to their first rows so the request stays reasonable, and the panel tells you when that happens.
Which files can the panel read?
.xlsx and .xlsm workbooks (the format GridCraft saves), and CSV, TSV and tab-delimited text. For .xlsb or .ods files, open them in GridCraft first and save; the saved copy is an .xlsx the panel can read.
Can the AI change my spreadsheet directly?
No. GridCraft’s browser build has no interface that lets another program edit a workbook, and the panel doesn’t pretend otherwise. You stay in control: paste a formula into the cell you choose, paste a table at the cell you select, or open a generated table as a new workbook.
Why does a request fail with a CORS or network error?
The custom provider option needs an API that accepts requests from browsers. OpenAI, Google Gemini and OpenRouter all do. Some self-hosted or regional gateways don’t; use one of the built-in providers instead.
New to GridCraft? Start with opening an XLSX file online, or see all guides.