Combine multiple CSV exports into one clean dataset for import into warehouse applications or LibreOffice Base.

This utility allows users to merge multiple CSV files (clients, suppliers, products) into a unified table, ready for upload or integration with desktop warehouse tools. It helps consolidate master data and reduces formatting inconsistencies.

Made with the help of ChatGPT.

General Description

Due to the fact that a data retrieval session using web-apps on our site ends when exporting to .csv and closing the browser, the presence of this application is required .
This lightweight web application allows you to easily concatenate two .csv files with similar structure (same headers and number of columns). 

It runs entirely in the browser without requiring installation —ideal for quick, local data processing.

See also: "Simple Warehouse Manager Template"

See also : "Web App Usage Patterns"

Main Features

• Upload two CSV files with same structure

• Automatic header validation.

• Automatically detects the larger file by row count.

• Concatenates in this order: larger file + smaller file.

• Downloads the resulting file as a .csv file

Advantages

• No installation, servers, or databases needed.

• 100% offline – your data stays on your device.

• Fast and intuitive interface.

• Works on all operating systems (Windows, Mac, Linux).

• Easily customizable for additional scenarios.

Push the button bellow and choose two .csv files with the same format to concatenate them :