Knowledgebase
How to export and import products and customers in Magento
Magento has options which you can use to export and import products and customers. You can do that either to move products/customers from one installation to another, or you can use it to update more quickly the values of product/customer settings in the same installation.
To export products or customers, in the admin panel of Magento go to System>Import/Export>Export. On the page that opens select Products or Customers, depending on what you want to export, from the Entity Type drop-down menu. A list of all the attributes/settings related to that type will appear. Click on the Continue button under the list to save the products/customers on your local computer. The information is saved in a CSV file (comma-separated values).
To import products/customers in the same or a different Magento instance, in the admin panel go to System>Import/Export>Import. On the page that opens select whether you want to import products or customers from the Entity Type drop-down menu. If you want to add new products/customers or update existing ones, from the Import Behavior drop-down menu select Append Complex Data or Replace Existing Complex Data. Then click on the Browse button to find the CSV file on your local computer. After that click on the Check Data button that's in the upper right corner of the page. If something in the CSV file is not compatible with the installation into which you want to import it, you'll receive an error message listing the reasons for the errors and the rows in the CSV file that produced those errors. In case this happens you can edit the CSV file with an application such as Microsoft Excel or Open Office Spreadsheet and correct the errors. Then use the Browse button to locate the CSV file again, check it by clicking on the Check Data button and if there are no errors click on the Import button.
Keep in mind that if you're importing a CSV file into a different Magento instance than the one from which you exported it, you need to have in the new installation categories with the same names as the ones to which the products in the CSV file originally belonged. Alternatively, you can edit the CSV file and rename the product categories with ones that exist in the installation. The same is true for custom attributes and attribute sets. Bundle products cannot be imported and configurable products may also pose problems.
For more details and screenshots you can also read the tutorial on exporting/importing products and customers in Magento.