In layman terms, the higher you progress (in terms of worlds etc.) the harder it should be.
Stated otherwise, Zafaria should be harder than Celestia since the world comes after CL.
However, one's difficulty with a world is solely opinion as it's completely based on a numerous factors such as: Luck Availability of Friends Availability of Resources Time School Level
Those factors play into how difficult a particular world might be for you.
I can tell you though, the world is indeed shorter (or it'll at least feel that way) than Celestia though and does contain a few cheating bosses.
I agree with what Star Edward said, that being the case you can also complete side quests and missions to help you level up (and make it a bit easier) I would say that most worlds are designed to be completed in 10 levels so most people start Zafaria as a level 60 wizard. Can you do it before can you do it after? Yes and yes, but consider that when Zafaria was released the level cap was 60 so most wizards were starting out as a level 60 entering Zafaria.
If you are looking for extra experience I recommend just doing side quests or the entire side world of Grizzleheim/Wintertusk. (It offers decent experience.)
I agree with what Star Edward said, that being the case you can also complete side quests and missions to help you level up (and make it a bit easier) I would say that most worlds are designed to be completed in 10 levels so most people start Zafaria as a level 60 wizard. Can you do it before can you do it after? Yes and yes, but consider that when Zafaria was released the level cap was 60 so most wizards were starting out as a level 60 entering Zafaria.
If you are looking for extra experience I recommend just doing side quests or the entire side world of Grizzleheim/Wintertusk. (It offers decent experience.)
Good luck!
Thanks. Can you help me because Stormriven Hall is pretty hard for me.
If you're struggling with Celestia, then I suggest completing Wintertusk. You can get your 58 spell quest and your 58 pet quest before going to Zafaria.