Preview before apply
The merge shows its output before anything is committed, so header mismatches and surprises surface while it's still cheap to stop.
All use cases
Merge exports into one clean file.
Monthly exports, per-region lead lists, and split downloads always end up needing to live in one file. CSV Power Editor merges CSV and Excel files locally with a preview before anything is written — then dedupe, clean, and export the combined result as CSV or XLSX.
How to
Combine files in five steps.
- 1
Open the first file
Start with any of the files you want to combine — CSV or XLSX. Encodings and delimiters are detected automatically.
- 2
Bring in the rest
Import the other CSV or Excel files as new sheet tabs, keeping the current workbook open. Each source stays visible and inspectable.
- 3
Run the Merge Files tool
Use Merge Files from the Power Tools panel to combine the data, with a live preview of the result before you apply.
- 4
Clean the combined data
Merging exports usually creates repeats. Run Remove Duplicates with your key columns, trim spaces, and remove empty rows — each step previewed and undoable.
- 5
Export the result
Save the merged result as a single CSV, or as an XLSX workbook if you want to keep the source sheets as tabs alongside it.
Why it works
Merging is the start, not the finish.
Dedupe in the same pass
Combined exports overlap. Key-column dedupe and fuzzy matching run right after the merge in the same app, with the same undo stack.
Tabs keep sources honest
Source files stay visible as sheet tabs while you work, so you can always check where a row came from before trusting the merged output.
Local and reversible
Everything happens on your Mac with 50 levels of undo. No uploads, no waiting on a web converter, no file-size anxiety.
FAQ
Common questions.
Can I merge more than two files?
Yes. Import as many CSV or Excel files as tabs as you need, then run Merge Files to combine them.
Can I mix CSV and Excel files in one merge?
Yes. CSV and XLSX sources can sit side by side as tabs in the same workbook and be merged together.
How do I handle duplicates after merging?
Run Remove Duplicates with the key columns that define a unique record (like email or order ID), preview the matches, then apply. Fuzzy Duplicates catches near-matches with typos.
Will I lose my original files?
No. Sources are read into tabs and the merged output is saved as a new file via Save As. Originals stay untouched on disk.
Is it free?
The app is free to download with a 14-day full Pro trial. After the trial, free mode keeps files up to 300 rows fully editable, and a one-time $14.99 Lifetime Pro purchase unlocks larger files.
Keep going
Related guides.
Convert CSV to Excel (XLSX) on Mac
Open any CSV — semicolon, tab, or odd encoding — and save it as a clean Excel workbook.
Remove Duplicates from CSV Files
Find exact and fuzzy duplicate rows by key columns, preview what gets removed, then apply with undo.
Compare Two CSV Files on Mac
Get a reviewable compare workbook with matched keys, changed columns, and missing rows.