Need advice on what is the the main difference between Valium and xanax (alprazolam)?

Short vs long acting. Xanax (alprazolam) works for shorter periods, typically 4-6 hours, while valium works for 12-16 hours. Both are in the class of medications known as benzodiazepines, which work by increasing the effect of gaba, the generally inhibitory neurotransmitter in the brain.