--- contentType: howto --- # Get the binary data buffer The binary data buffer contains all the binary file data processed by a workflow. You need to access it if you want to perform operations on the binary data, such as: * Manipulating the data: for example, adding column headers to a CSV file. * Using the data in calculations: for example, calculating a hash value based on it. * Complex HTTP requests: for example, combining file upload with sending other data formats. You can access the buffer using n8n's `getBinaryDataBuffer()` function: ```js let binaryDataBufferItem = await this.helpers.getBinaryDataBuffer(itemIndex, binaryPropertyName); ``` You should always use the `getBinaryDataBuffer()` function, and avoid using older methods of directly accessing the buffer, such as targeting it with expressions like `items[0].binary.data.data`.