Skip to tool
All tools
FeuTex · free tools runs in-browser no bloat built by LiMiT

Free CSV Compare Tool

Paste or upload two CSVs and get a clean diff: added rows, removed rows, and changed rows. Choose row-by-row comparison or match rows by a key column (like id). Everything runs in your browser.

Category: Data · URL: /tools/free-csv-compare-tool.html
Use a header name (when Header row is on) or a 1-based column index.
Report will appear here.
Related tools
Privacy: runs locally in your browser. No uploads, no tracking scripts.

How to use

Pick a comparison mode, paste or upload CSV A and CSV B, then run the diff.

  1. Choose Compare mode: Key column (recommended) or Row index.
  2. Set Delimiter (comma by default) and whether your CSV has a Header row.
  3. If using Key column, enter the column name (with headers) or a 1-based column index.
  4. Click Compare to see the summary and a short list of examples.
Keywords this page targets (natural cluster): free csv compare tool, compare two csv files online, csv diff tool, csv compare by key column, compare csv rows, find differences between two csv files, csv added removed changed rows, csv comparator with headers, compare csv ignoring row order, csv delimiter semicolon compare, compare large csv files in browser, csv diff by id column, row by row csv comparison, csv mismatch finder, csv change detection tool, csv compare tool no upload, offline csv compare, csv compare and highlight differences, csv validation and compare, compare csv text paste
Secondary intents covered: Compare two CSV files without uploading them to a server, Detect added and removed rows between exports, Find which rows changed based on an ID/key column, Compare CSVs that use semicolon or tab delimiters, Ignore minor formatting differences (whitespace/case), Generate a short report you can copy into an issue or email, Check whether two CSVs are identical before importing, Spot duplicate keys that break key-based matching

FAQ

Is this CSV compare tool really free?

Yes. You can compare CSVs here without paying or signing up.

Does the comparison upload my CSV data?

No. The diff runs in your browser and the tool JavaScript does not send network requests.

What is “Key column” mode?

It matches rows using a unique column (like id) and reports which keys were added, removed, or changed.

What if my CSV uses semicolons or tabs?

Set the Delimiter field to ; for semicolons or paste a tab character for TSV.

How are “changed rows” detected?

A row is “changed” when any cell differs after applying options like Trim cells and Ignore case.

Why am I getting a duplicate key error?

Key mode requires unique keys. If the key column repeats, the tool can’t reliably match rows.

Can I compare CSVs without headers?

Yes. Turn off Header row and use a numeric key column index (1-based), or use Row index mode.