Drop two CSVs, pick the key column in each, choose a join type — inner, left, right or full outer — and get one merged file with columns from both. A proper join, not just an append.
VLOOKUP and append-and-pray don't cut it. This does a real relational join: match rows in A and B on a key, and combine their columns with the join semantics you choose.
Dataset A and Dataset B — CSV or Excel, parsed locally.
Choose the key column in each file and inner / left / right / full outer.
Get one merged CSV with A's columns plus B's (collisions suffixed). Or send it to a dashboard.
Match on a key and combine columns — the join you'd write in SQL, on two files.
Inner, left, right and full outer — keep matches only, or preserve unmatched rows from either side.
The key can be named differently in each file (e.g. id vs user_id) — pick each independently.
Columns that exist in both files are kept, with B's copy suffixed so nothing is silently overwritten.
Both files are joined in your browser. Nothing is uploaded.