Free Tool to Combine Multiple CSV Files
Upload 2 or more CSV files, get back one merged CSV — stacked row by row, with a "Source File" column so you can always tell which file each row came from.
Combine multiple CSV files into one
Monthly exports, per-region extracts, a folder of near-identical CSVs from the same recurring report — the usual next step is stacking them into one file before you can actually analyze them together. This reads every file you upload and concatenates them row by row into a single CSV.
What if the columns don't match exactly?
They don't have to. If one file has a column the others don't, that column still appears in the combined output — rows from files that didn't have it just get a blank value there, instead of the whole merge failing.
A worked example
Upload jan.csv (columns: name, age) and feb.csv (columns: name, age, city). The combined file has all three columns, a new Source File column reading "jan.csv" or "feb.csv" so you can trace every row back, and January's rows show a blank city since that file never had one.
Questions
Is this free?
Yes, completely free, no account or signup needed.
How many files can I combine at once?
Up to 20 files in one go, 4MB total across all of them.
Does it remove duplicate rows?
No — it only stacks the files together exactly as uploaded. If two files share identical rows, both copies stay in the combined output.
Is there a tool that does the opposite — splits one file apart?
Yes — the Split CSV into Multiple Files tool breaks one large CSV into several smaller ones.
Got your combined file? Build a dashboard from it now.
Upload it here, describe what you want, and get back a real, editable .pbip project — free, no Fabric or Copilot license needed.
More free tools: split CSV into multiple files · data profiler · CSV to JSON · see all →