CSV Merger Online - Free CSV Combine Tool

CSV Merger Tool

Merge multiple CSV files or pasted CSV blocks into one clean CSV file with headers, source labels and duplicate handling.

Merge CSV

Upload multiple CSV files or paste multiple CSV blocks separated by a line containing ---. For best results, use files with similar headers.

CSV Input and Merge Settings

Upload CSV Files You can select multiple CSV or TXT files.

Input Delimiter

Custom Delimiter

First Row

Merge Mode

Duplicate Rows

Source Column

Source Column Name

Output Delimiter

Output Headers

Header Match

Download File Name

Paste CSV Data To paste more than one CSV block, separate each block using a line with only three dashes: ---

0 Sources

0 Merged Rows

0 Columns

0 Duplicates Removed

Detected Sources

No CSV sources loaded yet Upload files or paste CSV blocks.

Merged CSV

Merge Report

JSON Preview

Output Headers

Merged Data Preview

No preview yet. Upload or paste CSV and click Merge CSV.

About This Tool

CSV Merger is a free online data tool that helps you combine multiple CSV files or pasted CSV blocks into one CSV file.

You can upload multiple CSV files, paste multiple CSV blocks separated by dashes, choose delimiter, use the first row as headers, merge by union columns, first file columns, common columns or column position. The tool can remove duplicate rows, add a source file column, choose output delimiter and include or remove headers from the exported CSV.

It also shows detected sources, merged row count, column count, duplicates removed, merged CSV output, JSON preview, output headers, table preview and a detailed merge report.

This tool is useful for developers, students, data analysts, spreadsheet users, database import preparation, email list management, product data consolidation and anyone who needs to combine CSV data quickly online.

How to Use CSV Merger

1. Upload multiple CSV files or paste CSV data.
2. If pasting multiple CSV blocks, separate each block with a line containing ---.
3. Choose the input delimiter such as comma, semicolon, tab, pipe or custom delimiter.
4. Choose whether the first row should be used as headers.
5. Choose merge mode such as union all columns, first file columns, common columns or column position.
6. Choose whether to remove duplicate rows.
7. Optionally add a source file column.
8. Click Merge CSV.
9. Review the merged CSV, preview, headers and report.
10. Copy or download the merged CSV.

Privacy Note: This CSV Merger works directly in your browser using JavaScript. The CSV files or pasted CSV data are processed on the page and are not submitted through a form by this tool.

Frequently Asked Questions

Is this CSV Merger free?

Yes. This CSV Merger is free to use and does not require signup.

Can I upload multiple CSV files?

Yes. You can select and upload multiple CSV or TXT files, and the tool will merge them directly in your browser.

Can I paste multiple CSV blocks?

Yes. Paste each CSV block and separate them using a line that contains only ---.

Can it merge CSV files with different columns?

Yes. Choose Union all columns to keep all columns from all sources. Missing values will be left blank.

Can I remove duplicate rows while merging?

Yes. Choose Remove duplicate rows and the tool will remove repeated merged rows.

Does this tool upload my CSV files to the server?

No. The CSV merging is done directly in your browser using JavaScript and the page does not submit your data through a form.