With CSV format you will be able to export your issues and import them into another Jira instance. You can choose the delimiter, select between Comma, Semicolon, Vertical bar or Caret.

Rows look like this

Every row in the CSV file is an issue, it does not matter the content type you are exporting.

All exported data (fields with single selection, fields with multiple selection and extra content) will render their values in a single data separated by the selected delimiter.

Extra content

Comments

Comments in the export include:

Comment data will be rendered in a single data separated by the selected delimiter.

Adapt data format before exporting

Date fields

Duration fields

Duration fields, such as time spent, aggregate time spent, time estimate, aggregate time estimate, time original estimate, aggregate time original estimate:

Transitions area - duration fields

Time in final status and Time in initial status: