Grammar for : It is easier said than done

Welcome.

The idiom, "It is easier said than done," is the full version. The sentence structure is not too unusual. It is the use of said alone as a predicate past participle that makes it a bit odd. But it is not the only use of said as a predicate. Consider the opposing idiom "No sooner said than done."

This idiom has the same structure as this comparison:
This shirt is more blue than green.
You could also exchange the simple adjectives for predicate past participles:
Champagne is better sipped than gulped.

If you are struggling with the meaning of the idiom, it can be paraphrased as "It is easier to describe a result than to achieve it."