Data & CSV

Combine CSV tables

Append two tables with matching headings or align a union of their columns.

Your inputs

First CSV

UTF-8 CSV/TSV stays on this device. First row contains unique headings; maximum 25 MB, 50,000 rows and 200 columns. Fully empty rows are ignored.

Up to 25 MB per file, 50,000 data rows, 200 columns and 2 million data cells. Fully blank rows and columns are ignored before row, column and cell limits are checked. Individual tools may have smaller result or chart limits.

Or choose a CSV file

First separator

Second CSV

UTF-8 CSV/TSV stays on this device. First row contains unique headings; maximum 25 MB, 50,000 rows and 200 columns. Fully empty rows are ignored.

Or choose a CSV file

Second separator

Column alignment

Results update as you type. Larger files run when you press Update result.

Processed on your device

Your result

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A clear answer. Here’s how.

Appends rows from the second CSV after the first, aligning exact heading names rather than positions. Strict mode requires the same heading set but permits different order. Union mode keeps first-table order and appends new second-table headings. Output is limited to 50,000 rows and 200 columns; values remain text.

See a worked example

Worked example

A fixed demonstration, separate from the values you enter above.

First CSV

ID,Name
001,Ada
002,Sam

First separator

Comma

Second CSV

Name,ID
Jo,003
Lee,004

Second separator

Comma

Column alignment

Same heading set required

Example result

Example result
ID	Name
001	Ada
002	Sam
003	Jo
004	Lee