How high does the flame go ?

I guess It is about 8 inches at first and reduces ans it during. Lasts about 3 hours before burning out.

What are the ingredients?

Its an isopropyl alcohol gel. No odor

Does this give off a bad odor like "Real Flame" brand does (after burning 1/2 way? I use rubbing alcohol to avoid the smell (and the cost).

no it does not smell of any odors

Does it make a crackling noise?

Competitive formulations for fireplace fuel gel include additives that cause color and a random cracking sound when burned. JellyFish Flame deliberately does not incorporate these light and heavy metal salts that are hazardous. They lower the quality and purity of the finished product. They also create environmental health and safety concerns. For this reason, JellyFish Flame does not offer formulations that have the color or sound. We believe jellyfish are quite and tranquil, and that is why our JellyFish Flame is clean, pure, and quiet.