Combine CSV Files

Merge Two CSV Files into One

Need to use Combine CSV Files right now?

Keeps a single header row and appends both files' data rows below it — no duplicate header in the middle.

No sign-upNo uploads 100% free

CSV file 1

CSV file 2

Merged CSV

Assumes both files share the same column headers — the second file's header row is skipped and only its data rows are appended.

Features

  • Runs entirely in your browser
  • Privacy-first — your data is never uploaded
  • Real-time, instant results
  • 100% free, no sign-up required
  • Works on desktop, tablet, and mobile
  • No installation needed

Who uses this tool?

AnalystsDevelopersOffice workersStudents

About Combine CSV Files

Data often arrives split across multiple CSV exports — a monthly sales report exported month by month, survey responses collected in separate batches, or data from two different sources that need to sit in one combined file for analysis. Combining them by hand means carefully copy-pasting rows while making sure the header doesn't get duplicated.

This tool takes two CSV inputs, checks that both share the same column structure, and merges them into a single CSV — keeping the first file's header row and appending the data rows from both files below it, so the result is ready to use directly in a spreadsheet or data pipeline without a leftover duplicate header row in the middle.

This assumes both CSV inputs use the same columns in the same order — merging files with genuinely different structures (different columns, different order) will produce a technically valid but misaligned CSV, since this tool doesn't reconcile mismatched schemas automatically. Check that both inputs share the same header before merging.

How it works

  1. Paste both CSV files. Paste the content of each CSV file into its own box.
  2. Review the merged result. See both files combined with a single header row.
  3. Copy the merged CSV. Copy the result for use in a spreadsheet or data pipeline.

Examples

Two matching files

Input

File 1: name,age / Alice,30 — File 2: name,age / Bob,25

Output

name,age
Alice,30
Bob,25

Frequently asked questions