---
schema_version: "1"
id: 3a4fcb39176e54455b835b40e230464130be1ce3ab560ee720dbc1d4d0a64ba1
title: Prepare Data Files
collection: developer
version: current
locale: en-us
portal_url: https://docs.salesforce.com/developer/current/en-us/analytics/bi-dev-guide-ext-data/guides/concept/bi-ext-data-prepare-data.md
canonical_url: https://developer.salesforce.com/docs/analytics/bi-dev-guide-ext-data/guide/bi-ext-data-prepare-data.html
source_site: developer.salesforce.com
content_type: documentation
content_hash: eaf6bfe691459bd5b28769de1135764dda72544f721e635b08f2dc1a10612d2b
products:
  - Analytics External Data API Developer Guide
  - analytics
---

# Prepare Data Files

To upload external data from .csv files into a dataset, first prepare your data files.

External data can be loaded into a dataset by preparing two files.

- A data file, which contains the external data, in comma-separated value (CSV) format
- An optional metadata .json file, which describes the structure of the data file

**note:** Providing a metadata file is recommended.

The data and metadata files are used to populate a dataset with the external data. For detailed information about formatting CSV data and JSON metadata, see the [External Data Metadata Overview](https://developer.salesforce.com/docs/atlas.en-us.bi_dev_guide_ext_data.meta/bi_dev_guide_ext_data/bi_ext_data_schema_overview).