> For the complete documentation index, see [llms.txt](https://www.csvpath.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.csvpath.org/topics/how-tos/validating-csv-and-excel/the-flightpath-data-examples/duplicates.md).

# Duplicates

CsvPath Validation Language examples of handling duplicate CSV/Excel data

{% hint style="warning" %}
**Try these examples yourself.** They are built into FlightPath Data. You can download FlightPath Data free from [Microsoft](https://apps.microsoft.com/detail/9P9PBPKZ4JDF) or [Apple](https://apps.apple.com/us/app/flightpath-data/id6745823097) or [Github](https://github.com/dk107dk/flightpath)
{% endhint %}

CsvPath Validation Language makes it easy to find duplicate data in CSV and Excel files. These csvpaths show how you can create validation rules quickly and easily.

<figure><img src="https://2402701329-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F6wzqgDHj9mZbFxabiEbc%2Fuploads%2F8S2d5ZHAucNS7VYpEMMe%2FScreenshot%202025-11-07%20at%201.48.09%E2%80%AFPM.png?alt=media&amp;token=ff6fade3-2e67-4898-bb9f-58ba3ee26d03" alt=""><figcaption></figcaption></figure>

* [Unique lines by headers](/topics/how-tos/validating-csv-and-excel/the-flightpath-data-examples/duplicates/unique-lines-by-headers.md)
* [Percent overlapping](/topics/how-tos/validating-csv-and-excel/the-flightpath-data-examples/duplicates/percent-overlapping.md)
* [Duplicate lines](/topics/how-tos/validating-csv-and-excel/the-flightpath-data-examples/duplicates/duplicate-lines.md)