Pokémon type chart as a JSON.

type-chart.json

{
  "normal": {
    "normal": 1,
    "fire": 1,
    "water": 1,
    "electric": 1,
    "grass": 1,
    "ice": 1,
    "fighting": 1,
    "poison": 1,
    "ground": 1,
    "flying": 1,
    "psychic": 1,
    "bug": 1,
    "rock": 0.5,
    "ghost": 0,
    "dragon": 1,
    "dark": 1,
    "steel": 0.5
  },
  "fire": {
    "normal": 1,
    "fire": 0.5,
    "water": 0.5,
    "electric": 1,
    "grass": 2,
    "ice": 2,
    "fighting": 1,
    "poison": 1,
    "ground": 1,
    "flying": 1,
    "psychic": 1,
    "bug": 2,
    "rock": 0.5,
    "ghost": 1,
    "dragon": 0.5,
    "dark": 1,
    "steel": 2
  },
  "water": {
    "normal": 1,
    "fire": 2,
    "water": 0.5,
    "electric": 1,
    "grass": 0.5,
    "ice": 1,
    "fighting": 1,
    "poison": 1,
    "ground": 2,
    "flying": 1,
    "psychic": 1,
    "bug": 1,
    "rock": 2,
    "ghost": 1,
    "dragon": 0.5,
    "dark": 1,
    "steel": 1
  },
  "electric": {
    "normal": 1,
    "fire": 1,
    "water": 2,
    "electric": 0.5,
    "grass": 0.5,
    "ice": 1,
    "fighting": 1,
    "poison": 1,
    "ground": 0,
    "flying": 2,
    "psychic": 1,
    "bug": 1,
    "rock": 1,
    "ghost": 1,
    "dragon": 0.5,
    "dark": 1,
    "steel": 1
  },
  "grass": {
    "normal": 1,
    "fire": 0.5,
    "water": 2,
    "electric": 1,
    "grass": 0.5,
    "ice": 1,
    "fighting": 1,
    "poison": 0.5,
    "ground": 2,
    "flying": 0.5,
    "psychic": 1,
    "bug": 0.5,
    "rock": 2,
    "ghost": 1,
    "dragon": 0.5,
    "dark": 1,
    "steel": 0.5
  },
  "ice": {
    "normal": 1,
    "fire": 0.5,
    "water": 0.5,
    "electric": 1,
    "grass": 2,
    "ice": 0.5,
    "fighting": 1,
    "poison": 1,
    "ground": 2,
    "flying": 2,
    "psychic": 1,
    "bug": 1,
    "rock": 1,
    "ghost": 1,
    "dragon": 2,
    "dark": 1,
    "steel": 0.5
  },
  "fighting": {
    "normal": 2,
    "fire": 1,
    "water": 1,
    "electric": 1,
    "grass": 1,
    "ice": 2,
    "fighting": 1,
    "poison": 0.5,
    "ground": 1,
    "flying": 0.5,
    "psychic": 0.5,
    "bug": 0.5,
    "rock": 2,
    "ghost": 0,
    "dragon": 1,
    "dark": 2,
    "steel": 2
  },
  "poison": {
    "normal": 1,
    "fire": 1,
    "water": 1,
    "electric": 1,
    "grass": 2,
    "ice": 1,
    "fighting": 1,
    "poison": 0.5,
    "ground": 0.5,
    "flying": 1,
    "psychic": 1,
    "bug": 1,
    "rock": 0.5,
    "ghost": 0.5,
    "dragon": 1,
    "dark": 1,
    "steel": 0
  },
  "ground": {
    "normal": 1,
    "fire": 2,
    "water": 1,
    "electric": 2,
    "grass": 0.5,
    "ice": 1,
    "fighting": 1,
    "poison": 2,
    "ground": 1,
    "flying": 0,
    "psychic": 1,
    "bug": 0.5,
    "rock": 2,
    "ghost": 1,
    "dragon": 1,
    "dark": 1,
    "steel": 2
  },
  "flying": {
    "normal": 1,
    "fire": 1,
    "water": 1,
    "electric": 0.5,
    "grass": 2,
    "ice": 1,
    "fighting": 2,
    "poison": 1,
    "ground": 1,
    "flying": 1,
    "psychic": 1,
    "bug": 2,
    "rock": 0.5,
    "ghost": 1,
    "dragon": 1,
    "dark": 1,
    "steel": 0.5
  },
  "psychic": {
    "normal": 1,
    "fire": 1,
    "water": 1,
    "electric": 1,
    "grass": 1,
    "ice": 1,
    "fighting": 2,
    "poison": 2,
    "ground": 1,
    "flying": 1,
    "psychic": 0.5,
    "bug": 1,
    "rock": 1,
    "ghost": 1,
    "dragon": 1,
    "dark": 0,
    "steel": 0.5
  },
  "bug": {
    "normal": 1,
    "fire": 0.5,
    "water": 1,
    "electric": 1,
    "grass": 2,
    "ice": 1,
    "fighting": 0.5,
    "poison": 0.5,
    "ground": 1,
    "flying": 0.5,
    "psychic": 2,
    "bug": 1,
    "rock": 1,
    "ghost": 0.5,
    "dragon": 1,
    "dark": 2,
    "steel": 0.5
  },
  "rock": {
    "normal": 1,
    "fire": 2,
    "water": 1,
    "electric": 1,
    "grass": 1,
    "ice": 2,
    "fighting": 0.5,
    "poison": 1,
    "ground": 0.5,
    "flying": 2,
    "psychic": 1,
    "bug": 2,
    "rock": 1,
    "ghost": 1,
    "dragon": 1,
    "dark": 1,
    "steel": 0.5
  },
  "ghost": {
    "normal": 0,
    "fire": 1,
    "water": 1,
    "electric": 1,
    "grass": 1,
    "ice": 1,
    "fighting": 1,
    "poison": 1,
    "ground": 1,
    "flying": 1,
    "psychic": 2,
    "bug": 1,
    "rock": 1,
    "ghost": 2,
    "dragon": 1,
    "dark": 0.5,
    "steel": 0.5
  },
  "dragon": {
    "normal": 1,
    "fire": 1,
    "water": 1,
    "electric": 1,
    "grass": 1,
    "ice": 1,
    "fighting": 1,
    "poison": 1,
    "ground": 1,
    "flying": 1,
    "psychic": 1,
    "bug": 1,
    "rock": 1,
    "ghost": 1,
    "dragon": 2,
    "dark": 1,
    "steel": 0.5
  },
  "dark": {
    "normal": 1,
    "fire": 1,
    "water": 1,
    "electric": 1,
    "grass": 1,
    "ice": 1,
    "fighting": 0.5,
    "poison": 1,
    "ground": 1,
    "flying": 1,
    "psychic": 2,
    "bug": 1,
    "rock": 1,
    "ghost": 2,
    "dragon": 1,
    "dark": 0.5,
    "steel": 0.5
  },
  "steel": {
    "normal": 1,
    "fire": 0.5,
    "water": 0.5,
    "electric": 0.5,
    "grass": 1,
    "ice": 2,
    "fighting": 1,
    "poison": 1,
    "ground": 1,
    "flying": 1,
    "psychic": 1,
    "bug": 1,
    "rock": 2,
    "ghost": 1,
    "dragon": 1,
    "dark": 1,
    "steel": 0.5
  }
}

Cool but how do I use it?

For example, if you wanna check the effectiveness of a ground move against an electric/water mon, you would use something like this:

var effectiveness = TYPE_CHART["ground"][TYPE_ORDER["electric"]] * TYPE_CHART["ground"][TYPE_ORDER["water"]];

This is a small data file I used long, long time ago when playing around with JS and Pokémon calculators. There's a lot that could be improved here.

Aha I see, thank you! I didnt really expect a response when I saw it was 10 years ago haha.
Im making my own little game so maybe I should do it like this.

Yeah, I was really surprised to see a comment here. lol

It's definitely better to rewrite this as a proper hash table, like TYPE_CHART = { "normal": { "normal": 1, "fire": 1, … }} so you don't need the auxiliary variables TYPES and TYPE_ORDER. I really cannot remember why I wrote it like this. D:

@megahypercat I ended up rewriting this thing as a proper JSON. I don't know what you wanna do with it, but please be aware this is super old, as there's no Fairy type in this chart and maybe some values are incorrect (Dark doesn't have 0.5 effectiveness against Steel anymore, etc). :D

thanks for updating it <3

Very useful. Made a JSON Gist with the inverse of this that shows the weaknesses of a type in the same format.

I love you