Inkwell Data / Merge & join
Merge and join files
Stack monthly exports into one file, or join two files on a shared column like a VLOOKUP that actually works. Mix CSV, Excel and JSON freely.
How it works
Stack appends the rows of every file into one table. Columns are matched by name (ignoring case and spaces), so files don't need the same column order. Columns missing from a file are left blank, and you can add a column showing which file each row came from.
Join combines two files side by side using a key column, like a database join or a VLOOKUP. Choose an inner join (only matching rows), a left join (all rows from the first file) or a full join (all rows from both).
Questions
Are my files uploaded anywhere?
No. Your file is read by your own browser and processed on your device. There is no server receiving your data, no account, and nothing is stored after you close the tab.
How do I combine multiple CSV files into one?
Add all the files, choose Stack, and download. Columns with the same name line up automatically, even if they are in a different order in each file.
Is a join the same as VLOOKUP?
A left join does what VLOOKUP does, but brings back every matching column at once and handles multiple matches properly instead of only returning the first.
What happens if both files have a column with the same name?
The key column appears once. Other columns that exist in both files get a suffix from the second file name so nothing is overwritten.
Can I merge Excel files with CSV files?
Yes. You can mix CSV, Excel, JSON and Parquet files in one merge.