Weight

Weight determines how much horizontal knockback a character is knocked back by, if damage is constant. Weight also determines vertical knockback, as well as falling speed. Weight classes are only truly present in Super Smash Flash 2; though some characters jump and fall at different heights in the original Super Smash Flash, the fact that all can be KO'ed at the minimum of 100% of damage with an up attack while remaining airborn completely nullifies actual weight classes.

Types of weight classes

 * Lightweights: Characters who fit into this category are knocked back father than middleweights and heavyweights and are relatively easy to KO than most characters. Notable examples include Kirby, Tails, and Pikachu. Characters who fit into this category are small, weak in damage output and knockback, fast, poor range, slow falling speed and great recoveries. Characters in this category are usually small animals or supernatural creatures (Black Mage and Kirby).


 * Middle-Lightweights: Characters who fit into this category are not as easy to KO as much as pure lightweights, but are easier to KO than middleweights. Notable examples include Sonic, Ness, and Lloyd. Characters in this category are usually moderately sized animals, women, or kids/teens.


 * Middleweights: Characters who fit into this category are moderately knocked back by attacks, with their weight playing little or no effect in how far they are knocked away. They are neither easy or hard to KO usually. The most notable example is Mario, but others include Naruto and Wario. Character who are middleweights normally have decent damage output, moderate size and speed, OK recoveries, moderate range, and are usually considered the most balanced of all characters. Characters who are in this category are usually human beings or anthropomorphic animals.


 * Middle-Heavyweights: Characters who fit into this category are characters who are harder to KO than middleweights, but are easier to KO than pure heavyweights. Notable examples include Link, Goku, and Ichigo. Characters in this category are usually tall and/or bulk men or relatively heavy animals.


 * Heavyweights: Characters who fit into this category are knocked back shorter by attacks then other characters who are middleweights or lightweights. They are relatively hard to KO most of the time in comparison to other weight classes. Examples of characters that are heavyweights are Mega Man, Yoshi, and Captain Falcon. Characters who fit into this category are usually big, strong in damage output and knockback, slow speed, fast falling speed, great range, and poor recoveries. Characters in this category are usually robots or large creatures.

In Super Smash Flash 2
Although these rankings are not completely determined, it was confirmed at which percentages these characters' where horizontally KO'd with Link's Forward Smash (after the attack connected). As of v0.9, Kirby is no longer the lightest, and is actually tied with Meta Knight for the 4th lightest character.

1. 119%

2.   116%

3.   115%

4.   114%

5.   112%

6.  111%

7-8.  111%

7-8.  111%

9.  109%

10., 108%

11.  105%

12-13.   104%

12-13.   104%

14.   103%

15-16.  102%

15-16. 102%

17-18. 101%

17-18.  101%

19.  99%

20.   98%

21-22-23.  96%

21-22-23. 96%

21-22-23.  96%

24. 95%

25. 92%