Softonic

CSV Merge Tool

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You have two CSV exports with the same columns, two months of orders, two marketplaces, two regional teams, and you need them as one file. This tool concatenates CSV B below CSV A and, by default, skips the header row of the second file so your combined output has exactly one set of column names on top and every row from both inputs below it.

How to merge two CSVs

  1. 1

    Paste CSV A

    This becomes the top block of the merged file, including its header row if present.

  2. 2

    Paste CSV B

    This is appended after CSV A. Use the checkbox to control whether its first row is treated as a header and skipped.

  3. 3

    Confirm columns match

    The tool does not re-order columns. Make sure both files have the same column order and count before merging.

  4. 4

    Copy the merged CSV

    Lines are joined with a single newline and you get one CSV ready to import anywhere.

Append vs join: which merge do you actually want?

Two CSVs can be combined in two fundamentally different ways. This tool does append, stacking rows on top of each other. It does not do join, which adds columns from one CSV to matching rows in another.

Type What it does Use when
Append Stack rows vertically Same columns, more data
Join Glue columns horizontally on a shared key Different columns, shared IDs

Before you merge: a 30-second checklist

  1. Column order matches. If CSV A is id,name,email and CSV B is id,email,name, the merge will silently misalign data. Reorder columns first with the Column Extractor.
  2. Delimiters match. Both files must use the same delimiter (comma). Tab-separated files will be treated as single-column CSVs.
  3. Line endings are consistent. The tool normalises on any Unicode line break, but mixed line endings can still confuse downstream parsers.
  4. Skip the second header. Leave the checkbox on unless CSV B is already header-less, otherwise you end up with a stray id,name,email row in the middle of your data.

Next steps after merging

  • Run the CSV Deduplicator to drop rows that appear in both inputs.
  • Sort the combined file by date or ID using the CSV Sorter so the order is predictable.
  • If you need more than two inputs, merge them two-by-two, each pass is cheap.

Frequently Asked Questions

The merge does not realign columns. If CSV A has id,name,email and CSV B has id,email,name, the output will mix emails and names. Reorder columns first with the CSV Column Extractor so both inputs share the same layout.

Not in one pass. Merge the first two into a new CSV, then merge that output with the third file, and so on. Each step is instant and the result stays valid.

No, identical rows in A and B are both kept. Run the CSV Deduplicator afterwards if you want a single copy of each row.

The CSVs are sent to our server to run the merge. They are not stored or shared, and they are not added to the page link.

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