What CSV Reconcile does
Compare two CSV exports by a key column and see exactly which rows were added, removed or changed, and which cells changed from what to what.
A weekly product export, a CRM list and a mailing list, a bank statement and a ledger: the same records exist in two files, and someone has to find out what differs. A plain line-by-line diff is no help, because one re-sorted row or one extra column makes every line look different. CSV Reconcile matches rows by a key you choose, such as an ID, SKU or email, and then compares the cells.
The result separates four things. Rows only in the second file are added, rows only in the first file are removed, rows present in both with different values are changed, and key values that appear more than once are ambiguous. Changed rows show only the cells that differ, as old -> new, with the numeric difference when both values are numbers. Rules decide what counts as a difference: whitespace, upper and lower case, empty versus N/A, 1,200.00 versus 1200, a tolerance of a few units or a percent, 10/05/2026 versus 2026-10-05, leading zeros in IDs.
Files are decoded and compared in your browser, so they are never uploaded. Free compares up to 25,000 rows per file and downloads CSV files and a Markdown summary. Pro is $29 once: 500,000 rows per file, an Excel report, an HTML report, SHA-256 fingerprints, saved profiles and batch comparison against a baseline. Duplicate keys are never guessed; you choose a second key column or opt in to matching them by position.
Popular uses
Each opens CSV Reconcile already set up for that job, with steps and answers for that case.
Free vs Pro
| Feature | Free $0 · no account |
Pro |
|---|---|---|
| Matches rows by one to three key columns, so a different row order is not reported as a change | Included | Included |
| Lists added, removed and changed rows; changed rows show only the cells that differ, as old -> new | Included | Included |
| Reports duplicate keys as ambiguous instead of guessing which row matches which | Included | Included |
| Comparison rules: trim whitespace, ignore case, treat empty and N/A as equal, numbers with an absolute or percent tolerance, dates in month-first or day-first order, leading zeros in the key | Included | Included |
| Ignore columns, and match columns that have different names in the two files | Included | Included |
| Reads comma, semicolon, tab and pipe separated files in UTF-8, UTF-16 or Windows-1252, up to 25,000 rows per file | Included | Included |
| Downloads CSV files of the changed, added and removed rows and of every difference, plus a Markdown summary | Included | Included |
| Compare files of up to 500,000 rows each (free: 25,000) | — | Pro |
| Excel (.xlsx) report with Summary, Changed, Added, Removed, Ambiguous, Rules and Fingerprints sheets | — | Pro |
| Standalone HTML report you can email or attach to a ticket | — | Pro |
| SHA-256 fingerprints of both files in the Excel, HTML and Markdown reports | — | Pro |
| Saved profiles: keep the key, ignored columns, column matches and rules for a recurring export (stored in your browser) | — | Pro |
| Batch: compare one baseline with up to 25 other files at once and download a table of counts per file | — | Pro |
Pro is $29, paid once. Checkout and the licence key are handled by Dodo Payments (merchant of record). By buying you agree to the Terms and Privacy Policy.
Questions
Is CSV Reconcile free?
Yes, with no account and no install. The free plan includes: Matches rows by one to three key columns, so a different row order is not reported as a change; Lists added, removed and changed rows; changed rows show only the cells that differ, as old -> new; Reports duplicate keys as ambiguous instead of guessing which row matches which; Comparison rules: trim whitespace, ignore case, treat empty and N/A as equal, numbers with an absolute or percent tolerance, dates in month-first or day-first order, leading zeros in the key; and 3 more. Pro ($29, paid once) adds: Compare files of up to 500,000 rows each (free: 25,000); Excel (.xlsx) report with Summary, Changed, Added, Removed, Ambiguous, Rules and Fingerprints sheets; Standalone HTML report you can email or attach to a ticket; SHA-256 fingerprints of both files in the Excel, HTML and Markdown reports; and 2 more.
Does CSV Reconcile upload my data?
No. Both files are read and compared in your browser and are never uploaded. We only measure which buttons are used. See the Privacy Policy for retention and deletion.
Do I need to install anything?
No. Open the page and start working. It works on desktop and mobile browsers.
How does the Pro licence work?
You pay once and receive a licence key by email from Dodo Payments (our merchant of record). Paste it under "Have a key?" inside the tool. One key works on up to 3 browsers; you can release a browser at any time to use the key elsewhere.
Why compare by key and not line by line?
A line diff treats a re-sorted file as entirely different. Matching on a key such as an ID makes row order irrelevant, and it lets the tool say which cell of which record changed.
What happens when a key appears more than once?
Those rows are listed as ambiguous and are not compared, because there is no way to know which row in one file belongs to which row in the other. Add a second key column, or turn on matching duplicates by position if the order is meaningful.
Which files can it read?
Comma, semicolon, tab and pipe separated text, with the first row as the header. The encoding is detected as UTF-8, UTF-16 or Windows-1252. It does not read .xlsx files; save the sheet as CSV first.
Can it compare columns that are named differently?
Yes. Columns with the same name (ignoring case) are matched automatically. For the rest, pick the matching column in the other file, including for the key.
How large can the files be?
Free compares up to 25,000 rows per file. Pro raises that to 500,000 rows per file. Both files are parsed and counted whatever their size, so you always see the row and column counts.
