The two characters to be compared are Viscount Alfred, Lord Goring from An Ideal Husband and Valentine Legend from Love for Love. Although Love for Love is an example of Restoration comedy, An Ideal Husband, even as a Victorian comedy of manners, holds true to the original traits that describe the quintessential dandy. This being said, let's explore what are those traits.

• Idleness -as members of the upper classes, dandies are mainly potential heirs to a title or to a fortune which they must brag about by showing off the fact that they are not held to the rules of the common man. Lord Goring's father, Earl Cavesham consistently calls him lazy. Valentine is also criticized by his father and is considered a "rake".
• Debtors- As with the character of Algernon Moncrieff in The Importance of Being Earnest, Lord Goring and Valentine seem to have a penchant for overspending. Goring is the most fashionable man of his set, while Valentine is an avid gambler. Both wish to escape creditors, not because they do not have the money to pay, but because paying would signify responsibility- and they do not like that.
• Ladies- We know that in The Ideal Husband, Goring shows a history of women that he loved and then lost. He is certainly no stranger to romancing the ladies. Similarly, Valentine's name says it all: he corrupts girls, attracts them and then leaves them. In modern terms, these two dandies are you typical "players".
• Carelessness- Goring shows through his wits that he could care less what his father thinks of him, whether it is good or bad: Ex: when he says I love talking about nothing, father. It is the only thing I know anything about. Yet, Goring holds a bit of dignity in that he helps his friend save his career and marriage. Valentine, on the other hand, cares about nothing at all: not his family, not the women, not his creditors, and maybe not even his friends. 
• Change- the dandies tend to change toward the end. In Oscar Wilde's plays they often either change by choice or by circumstances. In Congrave's play Valentine certainly changes as a result of love.
• Wit- the wit comes naturally to the dandy given that they are free-spirits that do as they wish and have a chance to fool people. They know people better than they may even know themselves. For this reason, the repartee of paradoxes and epigrams are a typical part of their conversation. After all, as upper-class men, how else could they entertain others at their respective social gatherings?

On and all, the two characters are extremely similar in that they follow the prototype of the dandy which, in reality, must be first credited to Congrave. Wilde may have used Congrave as his mold to create Lord Goring, Lord Darlington, Lord Henry, Algernon, and Ernest "in the city", among others. There are more similarities than differences and it is all due to the fact that a clear mold distinguishes the creation of the dandy as a character.