Standard CSV files have a comma (,) as a separator. The principle is one language per file. Please note that CSV files can be uploaded only to Software localization projects. The type is selected during the project creation:

CSV files should have the following columns:

The order of these columns does not matter when uploading CSV files via the Lokalise web interface. However, if you are using an API or a CLI, the columns must be provided in the order shown above.

Here's an example of a valid CSV file with two translation keys:

When you upload a CSV file via the web interface, you'll be able to choose what data each column contains (or ignore that column):

When you are ready, click Apply and perform the uploading as usual.