> ## Documentation Index
> Fetch the complete documentation index at: https://docs.refuel.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Adding datasets

In Refuel, a dataset is a collection of rows of structured/semi-structured data that you want to transform with LLMs.

## Upload a CSV file as a new dataset

You can upload a CSV file as a dataset to Refuel.

<iframe src="https://www.loom.com/embed/ee68f69057544ad295cd31b68f506c94?hideEmbedTopBar=true" frameBorder="0" allowFullScreen className="w-full aspect-video" />

If you have data with PII fields, you have the option to Remove the PII data before the dataset get ingested by Refuel.

## Append to an existing dataset

If you want to add additonal data to an existing dataset in Refuel, you can do so
by clicking on **Add to Dataset** button on the dataset page and uploading another CSV with new data.

<iframe src="https://www.loom.com/embed/d834325f6ff545e19416027013d79404?hideEmbedTopBar=true" frameBorder="0" allowFullScreen className="w-full aspect-video" />

## Preparing data for upload

Before you upload the file, make sure it is a valid CSV file with the following requirements:

* The file should have a header row to identify the column names.
* The file should be encoded in UTF-8.
* Maximum file size is 2GB. If you have a larger file, you can ingest it into Refuel via a [cloud storage integration](/guides/datasets/cloud_storage).