Find and Replace in CSV

Replace text in CSV columns

1. Add data with Paste CSV content, Drop a CSV file here, or browse files. The file picker accepts .csv and .txt.
2. Enter the existing value in Find and its replacement in Replace with.
3. Choose columns under Columns to search. Select all and Select none change the whole selection.
4. Set Case-sensitive, Match whole cell only, or Use regular expression (supports $1, $2 in replacement). Keep First row is a header checked when the first row contains column names.
5. Check Affected cells and Preview of result, then choose Export CSV or Export Change Log.

The result rebuilds when you edit the input, replacement, or matching options. Empty CSV content and an empty Find value produce no result. Selecting no columns stops processing with an error, and an invalid regular expression does the same.

How CSV find and replace matching works

With Use regular expression (supports $1, $2 in replacement) unchecked, Find is literal text. Substring matching replaces every occurrence in a selected cell, and matching ignores letter case unless Case-sensitive is checked. Match whole cell only replaces a cell only when its full value equals Find. Regex mode turns that checkbox off.

Selecting the city column and replacing the whole cell London with Boston changes Alice's city while leaving the email column alone:

Input:
name,email,city
Alice,[email protected],London
Bob,[email protected],Boston

Output:
name,email,city
Alice,[email protected],Boston
Bob,[email protected],Boston

Use regular expression (supports $1, $2 in replacement) uses JavaScript regular-expression syntax. The replacement can include captured groups such as $1 and $2. An invalid pattern prevents the result from being built.

What the CSV preview and change log show

The result reports Cells scanned, Cells changed, Rows affected, and Columns searched. Affected cells records each changed row, column, before value, and after value. The changed cells are highlighted in Preview of result.

Preview of result shows the first 100 output rows. The on-page change table shows the first 500 affected cells, while Export Change Log contains the complete change list. Export CSV writes the transformed table and quotes values that contain commas, double quotes, or line breaks.

CSV parsing limits and unchanged data

The parser expects comma-separated input. It recognizes commas inside quoted fields, doubled double quotes, and line breaks inside quoted fields. There is no delimiter selector. If First row is a header is checked, the first parsed row labels the columns and is excluded from replacement; otherwise the rows are searched as data.

Unchecked columns pass through unchanged. The tool changes cell values and does not repair general CSV structure. Selected files are read with FileReader, and the page has no fetch, XMLHttpRequest, sendBeacon, or form post for the CSV text, so processing stays in the browser.

When to use this CSV replacement tool

Use this page for a targeted value change, such as replacing an old email domain in one column while leaving names and cities unchanged. It also handles repeated status values when the replacement should apply only to selected columns.

For structural cleanup or another spreadsheet operation, open Spreadsheet Transform Tools. Find and Replace in CSV records the value before and after each change.

Frequently asked questions