Free online CSV merger to combine multiple CSV files by key. Supports left, inner and full joins, column selection and duplicate removal. All merging runs in your browser with no data uploaded, ideal for data analysis and reporting.
Select or drag and drop the CSV files you want to merge (supports multiple files).
Drag CSV files here or click to upload.
Multiple CSV files are supported.
CSV Merger is a lightweight tool designed specifically for data analysts and operations personnel. It solves the "header alignment" pain point when merging multiple reports. The engine uses index matching technology - even if column orders differ between files, as long as header names are the same, it intelligently categorizes data into the same columns. For large CSV files with thousands of rows, it still maintains millisecond-level merge response speed.
Perfect for data analysts consolidating reports from multiple sources, developers merging exported database tables, operations teams combining user data with transaction records, and finance teams matching invoices with payment records. Also ideal for merging survey results, inventory data, and any scenario requiring multi-source data integration.
The tool automatically identifies all column names that appear. For cells with missing data, empty values will be filled automatically.
Yes. We recommend using UTF-8 encoding to avoid garbled text. The tool automatically attempts to recognize common encodings during import.
There is no hard limit on rows, but the smoothness after merging depends on your browser's available memory.