How come some characters seem to suffer from more hitstun then others?

[Dr. Krumm]

How does this game calculate hitstun on characters? How come a character like Fox seem to have more hitstun then a character like Luigi?

Am I completely mistaken here or is this true? How does this game calculate hitstun?

 

[Kadano]

Fox appears to have more hitstun because his high gravity vector works against the knockback vector, effectively decreasing his upwards momentum.

 

[Dr. Krumm]

Ok! Very informative video! Thanks! :D

 

[Fortress | Sveet]

Hitstun is based on weight. So heavier characters will be actionable earlier than ligher characters would. This is shown in that video: knockback is inversely proportional to weight, and hitstun = (knockback * 0.4), thus hitstun is inversely proportional to weight.