Upload Excel Files
Uploading is the first step of the dataset wizard (Upload Raw Data). This is where you bring in the raw spreadsheets you want Transformer to clean and map into your schema.
Steps
Open the Upload step
In the New Dataset wizard, you start on the Upload Raw Data step (labelled Select Data: choose which files and worksheets to process).
Add your files
Select or drag in your raw files. Excel (.xlsx / .xls) and CSV files are
supported — no reformatting required.
Pick the worksheets
For multi-sheet Excel files, choose which worksheet(s) to process. You can preview the first rows of each sheet to confirm you’ve selected the right data.
(Optional) Add global AI instructions
Open Global AI Instructions to give the transformer extra guidance that applies to the whole upload — for example how to interpret ambiguous columns or which rows to ignore.
Continue to processing
Proceed to the Processing step. AI transforms the raw rows and determines the mapping into your target schema automatically.
Transformer only sends the column headers and a small sample of rows to the AI for mapping — never the entire file. All data manipulation happens on disk, and the data itself is written to BigQuery rather than stored in the app database.
Next step
After processing and review, the final step is merging the result: Add to Main Schema →