Match records by their identifier, even when the rows move. Find additions, removals, and changed values without uploading your files.
No account required
Processing stays in this browser
Free JSON report
Compare CSV files by ID
Per input: 500 data rows, 200 KB (200,000 bytes), 200 columns. UTF-8, comma-separated, with a header row.
Example data only: fictional accounts demonstrating one added, one removed, and one changed record.
Choose a stable ID such as account_id or SKU. Values and IDs are compared as exact text, preserving leading zeros. Duplicate and blank IDs are excluded and reported.
Start with your own CSV exports or load the clearly labeled example.
Your comparison
Added means present only in after. Removed means present only in before.
Added
0
Removed
0
Changed
0
Unchanged
0
Excluded rows
0
Change
Identifier
Details
Resolve these identifiers before reconciling
Show every excluded source record
The JSON download includes every result: added, removed, changed, unchanged, excluded records, and columns found in only one input. Record numbers count CSV records, including the header; quoted multiline values can span several physical lines. Save reports carefully: they contain your source values.
Shares the public page address only. Your data is never included.
Know what you are comparing
A record comparison, even when the rows move.
Match by ID, not by line number
A CRM export may sort accounts differently each week. A line-by-line comparison can make unchanged records look different. Choose the column that identifies an account, product, or other record: this tool matches that ID across the two files before checking its shared fields.
For example, if account 001 moves from row 2 to row 50 but its values are identical, it remains unchanged. An ID of 001 is different from 1; leading zeros, spaces, and letter case are preserved.
Duplicates need a decision
If an ID appears twice in either input, every row with that ID on both sides is excluded from additions, removals, and field changes. Pairing those records automatically could invent a result. Empty or whitespace-only IDs are also excluded.
The result lists those source records, and the JSON includes their original values. Correct the source or choose a genuinely unique identifier, then run the comparison again.
Understand field and format differences
The first record must contain unique, nonblank column headers. Headers match exactly. Quoted commas, escaped double quotes, and line breaks inside quoted fields are supported. Malformed quoting and uneven row lengths produce an error before comparison.
Only shared non-ID columns contribute to changed-record counts. Columns added to or removed from the export are reported separately. Excel workbooks, semicolon-delimited files, fuzzy matching, and automatic cleanup are outside this free tool's scope.
Your files stay with you
The comparison runs in this page. CSV contents are not uploaded, put in a link, or saved by the tool. Clear everything to remove the working inputs and results. A JSON report you download stays on your device until you delete it.
This public website still loads its normal page assets and honors your site privacy preferences. The downloaded Data Workbench can run entirely offline after purchase.
For the next export, too
Need larger files and repeatable reports?
The free tool handles small spot checks. Data Workbench adds more capacity and reusable comparison settings for recurring work. Choose the offline Browser Workbench or the Reconciliation Kit for developers, each a separate $49 one-time purchase.
Capability
This free tool
Data Workbench
Rows per input
500
50,000
Size per input
200 KB
5 MB
Reports
Complete JSON
CSV and JSON
Saved settings
Choose ID each time
Export and reuse settings
File formats
Comma-separated UTF-8
Comma, semicolon, tab-separated UTF-8
Offline use
Public web page
Downloaded browser app or developer kit
Paid limits also include 200 columns and 1 million cells per file. Paid detail exports include up to 5,000 findings, with truncation disclosed and complete summary counts. The browser app and developer kit are sold separately; see the product page for each license and scope.