Expiration Date. First, if you still have the packaging for the chicken, double-check the sell-by date to determine how long the manufacturer recommends the chicken is good for. It is recommended that if your raw chicken has sat in the fridge, for more than 1 to 2 days since the date of purchase, it is likely begun to go bad.
Unpleasant Smells. Another sign that your chicken has likely gone bad, is if there is a foul smell to the chicken. By foul, I don’t mean that it IS chicken, I mean that it smells bad! If you give the chicken a sniff test, and the smell of chicken is very strong, or nasty, then it has gone bad and should not be eaten.
Slimy Texture. You can also check the texture of the chicken. Chicken in general has a slimy texture to it, but if it is extra slimy chicken, then it is likely not safe to eat.
Color of the Chicken. Then as mentioned above, another great way to tell if your chicken is safe to eat or not is to examine the color of the meat. In general, raw chicken should have a light pink, or white-ish color to the raw meat. If you see any signs of yellow, green, gray, blue, or mold growing, then the chicken is not safe to eat.
These different methods to check for signs of spoilage are both in raw chicken and cooked chicken. The safest bet, if you see one or more of these signs of spoilage present, is to not risk eating the chicken, and throw it away.