Common questions

Open the CSV in Qinsio's dedupe tool, click "Find duplicates", and it scans every row against every other row using an exact full-row hash — no formulas, no pivot tables. Results show which rows are duplicates, grouped together, so you can review them before downloading the cleaned file. If you prefer doing it manually in Excel, you can use the COUNTIFS function or conditional formatting to highlight repeated values, though that only works per-column rather than across the full row.

Upload both files to Qinsio's compare tool, map which columns correspond to each other, mark a key column (the unique identifier like an invoice ID or customer code), and click "Find mismatches". It returns changed values, rows that exist only in one file, and a downloadable report. Alternatively, Excel's built-in Inquire add-in can compare workbooks, but it requires the Office desktop app and doesn't handle CSV files.

Yes — Qinsio processes everything directly in your browser. Your file is never sent to a server; the comparison runs inside the browser tab itself using a Web Worker. This makes it suitable for finance teams handling confidential invoice data, since the file stays on your machine the entire time.

Load both files into Qinsio's compare mode and map the columns you want to match. The tool identifies which rows match on your chosen key, then flags any cells where the values differ between the two files. There are no VLOOKUP or INDEX/MATCH formulas to write — you get a plain list of discrepancies you can download and hand off directly.

Qinsio's compare tool is free to use for files up to 50,000 rows. You upload both CSVs, map columns, and get a full mismatch report at no cost. There's no account required for the free tier. For very high-volume or recurring reconciliation workflows, paid plans are available.

Qinsio supports files up to 50,000 rows. Files with 20,000 rows or more may take 30–60 seconds to process since everything runs locally in your browser rather than on a server, so processing speed depends on your device. Files beyond the 50,000-row limit will be truncated at that boundary with a visible warning, so you always know exactly what was checked.

If you just need to convert formats without finding duplicates or mismatches, you can use our free CSV ↔ Excel Converter. Just drop your file, and it instantly converts it locally in your browser. Try the converter here.

No installation needed. Qinsio runs entirely in your browser — open the page, drop in a file, and start. It works on any modern browser (Chrome, Firefox, Safari, Edge) on desktop. There's no software to download, no account to create for basic use, and nothing that runs on a server.

Duplicate detection works on a single file and flags rows that appear more than once — useful for cleaning a customer list, invoice register, or any dataset where each record should be unique. Mismatch detection works across two separate files and flags rows where the same record (matched by a key column) has different values in one file vs. the other — useful for reconciling a bank statement against a ledger, or checking whether two exports of the same data actually agree.