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CSV Merger

Drag in 50 CSV files with mismatched columns and merge them into one unified table.

Drag & drop multiple CSV files here

or click to browse · Max 50 files · 2GB limit

How CSV Merger Works

  • ●Union by Name — Columns are intelligently aligned by header name, not position. Missing columns are auto-filled with NULL.
  • ●Schema Detection — First 20,480 rows of each file are sampled to detect column types, balancing accuracy and speed.
  • ●100% Local — Powered by DuckDB WebAssembly. No data leaves your browser.
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