Reducing requests and size.
WHAT MINIFICATION DOES
Removes spaces, line breaks and comments from code files.
Makes them smaller with no change in behaviour.
WHAT COMBINING DOES
Merges multiple files into one, reducing the number of requests.
WHY IT HELPS
Fewer, smaller files load faster.
WHY IT BREAKS THINGS
Combining files changes the order in which code runs.
Some scripts depend on that order and fail.
HOW TO DO IT SAFELY
Enable minification first, test everything Then enable combining, test everything again If something breaks, disable the last thing you enabled
WHAT TO TEST
Every page type Forms The checkout
Anything interactive: sliders, menus, filters
IF SOMETHING BREAKS AND YOU CANNOT FIND IT
Most plugins allow excluding specific files from minification.
WHETHER IT IS WORTH IT
The gain is modest compared with images and caching.
Do those first.
