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CSV Merger

Combine multiple CSV files or text blocks into a single CSV. Handles different column sets and optionally removes duplicates.

Sources: 0 Total rows: 0 Columns: 0
Merged CSV

About CSV Merger

The CSV Merger stacks multiple CSV files vertically into one. It automatically handles CSV files with different column sets by using the union of all columns and filling missing values with empty cells. Each source file's header row is used once in the output.

How to Use

  1. Upload or paste the first CSV.
  2. Upload or paste the second CSV.
  3. Choose whether to merge by appending rows (vertical stack) or joining on a key column.
  4. Click Merge - the combined CSV appears in the output.
  5. Download or copy the merged result.

How It Works

For row appending: rows from both CSVs are combined. If headers differ, the union of all headers is used as the merged header and missing values are left empty. For key-based join: matching rows are combined side by side on a shared key column.

Example

Merge two monthly sales exports (January.csv and February.csv) by appending rows to get a full Q1 report with all records from both months in one file.

FAQ

The merged output uses all unique column names across all source files. Rows from a file that doesn't have a given column will have an empty value for that column.
Yes - two rows are considered duplicates only if every cell value matches exactly (case-sensitive).
No. Everything happens in your browser. Your data never leaves your device.