Compare Inventory and Stock Files Between Two Dates
Two stock exports, one question: what changed? A key match answers it in a minute.
Operations and e-commerce teams get stock lists from a warehouse system, a supplier and a store platform. They rarely agree, and finding the difference by hand across thousands of SKUs is slow.
Load both files in Data Comparison and choose the SKU or product code as the key. It shows added items, removed items and items where a value such as quantity or price changed. Use the options to trim spaces and ignore case, and set a number tolerance if small differences are fine.
Prepare first. Make sure the SKU is unique in each file and stored as text so leading zeros are kept. Remove duplicate rows with Data Transformation, and use the same column names in both files. If a supplier file uses another format, convert it with the Format Converter.
Read results with care. A removed item might be sold out, renamed or mistyped. Use the comparison to find the cases to check, then confirm with the source system. Your files stay in the browser.
Related tool pages
- Compare Two CSV Files: Compare two CSV or Excel files by a key column and see added, removed and changed rows. Free, runs in your browser.
- Compare Two Excel Files: Compare two Excel (.xlsx) files by a key column and see every added, removed and changed row and cell. Free, and your files stay in your browser.
- CSV Diff Tool: Find the differences between two CSV files online: which rows were added, removed or changed, cell by cell. Free, in your browser.
How to use the Data Comparison: step by step
- Open Data Comparison and load both files.
- Choose the SKU column as the key.
- Set trim, case and tolerance options.
- Review the differences and confirm them at the source.
When to use the Data Comparison
- Reconcile warehouse and store stock
- Check a supplier price list against yours
- See what changed since last week
- Find items missing from a feed
Example
Input: before.csv + after.csv, key = id
Output: Added 3 · Removed 2 · Changed 5
Frequently asked questions
Can the files be different formats?
Yes. A can be a CSV and B an Excel file. Columns are matched by name. JSON and Parquet files are not supported here, so convert them to CSV first.
How does Data Comparison find differences?
It matches rows by a key column, or by the first two columns, and shows which rows were added, removed or changed, down to the cell. It works with CSV and Excel files.
Tip: Keep SKUs as text so codes like 00123 do not lose their zeros.