Difference between “laden” and “loaded”

While each has specific meanings that are not shared (eg "loaded" for "rich"), in their central meaning they are synonymous. (The Oxford English Dictionary uses each of the two as one of the words to define the other).

"Laden" tends to be more poetic, but it can still be used in ordinary speech.

According to Merriam-Webster laden means

loaded heavily with something: having or carrying a large amount of something.

It is something more than just being loaded. Furthermore, the term seems to be used more often in poetry than common conversations.

In this case, looking at the synonyms of the words is most revealing.

On Merriam-Webster, loaded has synonyms like "brimming", "full" and "jam-packed". Laden, on the other hand, has synonyms like "burden", "encumber", and "weight.

The connotation when you say "the tree was loaded with fruit" is positive: the tree is full of fruit, which means there's plenty to go around. When you say "the tree was laden with fruit", it's implying that the tree's branches are weighed down by their burden of fruit.

Think of it more as volume (loaded) and mass (laden). If the jar is filled with cookies, it is loaded, but hardly laden. Whereas the 54' commercial hauling trailer carrying 25 tons of cookies is not overly laden, but is surely loaded.