Merge Previewer
See exactly what merging several CSV files would produce before you commit — combined row count, column mismatches, and a sample result.
How to use Merge Previewer
- Start by providing the required input: Drop 2 or more CSV files.
- No additional settings need to be configured.
- Run the tool with Preview Merge.
- Review the result or preview on the page and confirm it matches your input before using or sharing it.
Checking before you commit to a merge, not after
Merging several CSV files only to discover afterward that their columns didn't actually line up means redoing the work — and sometimes means you've already lost track of which rows came from which file. Previewing the merge first, with mismatches called out explicitly, catches that before anything is actually combined.
What the projected row count tells you
Seeing the total row count the merge would produce, before running it, is a quick sanity check on its own — a number far higher or lower than expected is often the first sign something about the source files isn't what you assumed.
Does this actually perform the merge?
No — it's a dry-run preview only; use Data Combiner (or another merge tool) separately to perform the actual merge once the preview looks right.
What exactly counts as a "mismatch"?
Any file whose column headers — names or order — don't exactly match the first file's headers.
Can I preview more than two files at once?
Yes — add as many files as you're planning to merge; every one is checked against the first file's schema.