Frankenstein is a lot older then Dracula

Because of their Iconic Universal Films both coming out in 1931, and then Hammer doing their versions close to each other, then the 90s 'put name of book Author in film title' versions (and as a Weeb I should add their Toei Anime TV movies).  We tend to think of their histories as being parallel.  But they weren't always.

In 1931 Dracula was in the grand scheme of things still a fairly new addition to popular culture.  The same age Harry Potter and Pokémon will be in 2031, and about the same age Late 80s stuff is now, or Star Wars a decade ago when the Disney buyout first happened.  There were people alive in 1931 who remembered when the original book came out, in fact Bela Lugosi himself was a teenager then but not in the right region to have likely read it that early.  Also Stoker's wife was still alive when it's sorta sequel was made.

For Frankenstein however, 1931 was the same year as the Centennial of the Novel's THIRD edition.  There is still less time separating us from the Universal Film then separated the Universal Film from the original novel's publication in 1818.  The Creature being popularly thought of as a tall green skinned flat headed monster with bolts in his neck has been the case for less then half his existence thus far.

This fact is technically well known, but I don't think we often process the implications of that, we think of the Universal Film as still close to the beginning of Frankenstein's cultural legacy, even though it's very much not.

Between the novel's 1st and 3rd edition was a Stage version in 1823 called Presumption; or, the Fate of Frankenstein.  A lot of the pop culture Frankenstein mythology not in the book which many assume began with the 1931 film is actually already in that 1823 play, like the Creature being created in a Castle.  Mary Shelly's own comments on the play cite a memorable moment being the Doctor shouting "IT LIVES!!!!!".  The actor who played The Creature in that version passed away 20 years before Boris Karloff was born.

Ya know the not in the Book trope of Dr. Frankenstein having a Hunchbacked assistant named Igor?  Well Igor being the name originated with Ygor played by Bela Lugosi in 1939's Son of Frankenstein.  In the 1931 Universal film that character was named Fritz and played by Dwight Frye, and that was also his name in the 1823 stage play.  Fritz was the name of this character for longer then Igor has been, it was Fritz for over a century but one Bela Lugosi performance changed it forever.

An 1826 French Play by Charles Nodier called Le Monstre et le Magicien (The Monster and the Magician) is considered an unofficial adaptation of Frankenstein by the people at BlackCoatPress.  Frank Morlock wrote an English translation and they published it alongside Hugo's own Notre-Dame de Paris stage version (the same one Lindsay Ellis talked about) in a volume called Frankenstein Meets The Hunchback of Notre-Dame, the title being justified by a thrown in original short story by Morlock himself.

But guess what, Frankenstein and his Creature had even already encountered a Vampire a decade before Dracula was published in the 1887 musical burlesque Frankenstein, or The Vampire's Victim.  This YT video features a song from it.

That of course brings us to how if you defined Dracula by more then just the name and consider him him an evolution of Lord Ruthven, he can be considered exactly as old as Frankenstein being born from the same legendary Ghost Story competition in 1817, and did get a lot more Stage versions in between.  For more on that subject I recommend the book Stage Blood: Vampires of the 19th-Century Stage by Roxana Stuart, and also the translations of French Ruthven productions published by BlackCoatPress, the plays translated by Frank Morlock and a Novel by Brian Stableford.