Sheila Katzaman6,441 Points
Does adding extra space cause slower web page load time?
Steven Parker195,787 Points
The loading time is a factor of the total number of characters, both visible and white space.
A standard optimizing practice is to reduce file size which includes removing all unnecessary white space. A file processed this way is called "minified", and there are several utilities available to assist with this both online and downloadable.
Minified files are difficult to maintain, so the original source should always be kept for doing any further development. The updated file can be minified again before publishing.