CSV Merger
CSV Merger.
Merge multiple CSV files with header union and row append.
Your files never leave your device
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What it does
Merge multiple CSV files with header union and row append.
Why use it
CSV Merger helps you merge csv files online in your browser — fast, private, no upload required.
Example input
File 1: name,email Alice,alice@example.com File 2: name,email Bob,bob@example.com
Example output
name,email,signup_date Alice,alice@example.com,2024-01-15 Bob,bob@example.com,2024-02-01 … 2 files merged · 4 total rows
Frequently Asked Questions
Is my data uploaded when using CSV Merger?
No. All processing runs locally in your browser. Your files never leave your device.
Do I need an account?
No account is required. All tools are free and work instantly.