How to Merge CSV Data by Column Online (Without Excel or Code)

Oct 26, 2025 2 min read

Merging rows in a CSV file by a column such as “Department” is a common task when you are stitching together exports from different tools. It lets you consolidate repeated entries and summarise totals without opening Excel or writing a quick Python script.

Below is a simple example of the raw input many teams start with:

Department,Sales,Month
Sales,2000,Jan
Support,1200,Jan
Sales,3000,Feb
Support,1500,Feb

Each department appears in multiple rows. By merging on the Department column you can produce a roll-up that is easier to scan, share and reason about.

Why merge rows in a CSV?

When data comes from multiple sources or time periods, the same entity may appear several times. Examples include:

  • Department-level revenue exported every month.
  • Customers with repeated purchases across different channels.
  • Campaign performance split across regions.

Grouping these rows keeps the most relevant information in one place and reduces the manual clean-up time that usually happens in spreadsheets.

Merge the data online with SifterAI

SifterAI helps you merge CSV data in the browser using a plain-language instruction. No plugins or macros required.

  1. Upload your CSV. Drag the file into SifterAI or pick it from your computer.
  2. Describe the merge in English. Enter an instruction such as:
    group the rows by Department and sum the Sales column, show the total sales per department
  3. Preview the result. SifterAI runs the transformation and shows the merged table. If you need to adjust (for example, rename columns or sort descending), just tweak the instruction and preview again.
  4. Download the full CSV. Once the preview looks right, purchase the $1 download and save the merged dataset.

The end result is a concise table, for example:

Department,Total Sales
Sales,5000
Support,2700

That output can be imported back into your BI tool, shared with your team, or used as the base for the next workflow.

If you are working with a different structure—say, merging by Customer ID or consolidating Units Sold—simply adjust the column names in your instruction. SifterAI handles the rest so you can stay focused on the analysis, not the mechanics.