How do I compare two CSV files and see which rows changed?

Paste or upload the files into Original (A) and Updated (B). Choose the key column under Match rows by. The result lists Added, Removed and Changed rows, showing old and new values for changed fields.

Which file types and delimiters can I compare?

Upload accepts .csv, .tsv and .xlsx files, reading the first sheet of a spreadsheet. Delimiter is auto-detected among comma, semicolon, tab and pipe, or you can set it manually.

How do I compare CSVs that have no unique ID column?

Tick more than one key column, or change Compare to Row by row position or Whole rows, any order. The last option lists rows that exist in only one file.

How do I stop trivial differences like case, spaces or 1.0 vs 1 showing as changes?

Use the options Ignore case, Trim whitespace around cells, and Treat numbers as equal when numerically equal. Each one normalizes cells before comparing.

Why do I get a warning about repeated or empty key values?

Repeated key values are paired in order, first with first. Rows with an empty key are excluded. Add more key columns or compare by row position to cover every row.

Yes. Every tool is free to use, with no account and no credit card. The work runs on your device rather than on our servers, which is what keeps it free to run.

Does it work on mobile?

Yes. It runs in current mobile browsers on iOS and Android, with nothing to install.

🔀

Free CSV Diff

Compare two CSV files by a key column and see exactly which rows were added, removed, or changed — with the specific fields that differ shown old to new. Handles quoted fields; runs entirely in your browser.

Runs in your browserNo sign-up, no pop-upsNo login requiredFree forever

Works offline once loaded

Original (A)

Updated (B)

Delimiter

Encoding

Compare

Match rows by — Key columns (tick one or more)

idnameemailplan

First row is a headerIgnore caseTrim whitespace around cellsTreat numbers as equal when numerically equal (1.0 = 1, 1,5 = 1.5)

Added

Removed

Changed

Export delimiter

Show only changed columns

Changed rows

id	name	email	plan
1	Ada Lovelace	ada@example.com	proenterprise

Showing 1 of 1

Added rows

4, Katherine Johnson, katherine@example.com, free

Showing 1 of 1

Removed rows

2, Alan Turing, alan@example.com, free

Showing 1 of 1

💡 Rows are matched by the key column, so reordering doesn't register as a change — only added, removed, or edited rows do. Quoted fields with commas are handled. Runs entirely in your browser.

How It Works

Compares two CSVs by a key column and reports exactly which rows were added, removed, or changed — and for changed rows, which fields differ. Reordering rows does not count as a change.

1
Paste both CSVs
The original (A) and the updated version (B). The first row is treated as the header.
2
Pick the key column
Choose the column that uniquely identifies a row (e.g. an id or email). Rows are matched on that key, so order does not matter.
3
Read the diff
See counts of added / removed / changed rows, with changed fields shown old → new. Quoted fields containing commas are handled.

Both files are parsed and compared in your browser. Nothing is uploaded.