Dynamic Height Issue for UITableView Cells (Swift)

Try This:

func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    return UITableViewAutomaticDimension
}

EDIT

func tableView(tableView: UITableView, estimatedHeightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    return UITableViewAutomaticDimension
}

Swift 4

func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
    return UITableViewAutomaticDimension
}

Swift 4.2

func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
    return UITableView.automaticDimension
}

Define above Both Methods.
It solves the problem.

PS: Top and bottom constraints is required for this to work.

Here is example

Use this:

tableView.rowHeight = UITableViewAutomaticDimension
tableView.estimatedRowHeight = 300

and don't use: heightForRowAtIndexPath delegate function

Also, in the storyboard don't set the height of the label that contains a large amount of data. Give it top, bottom, leading, trailing constraints.