Over time, I am starting to appreciate the art of having less clutter as well as recipes that require fewer ingredients. I am in the mist of trying to narrow down my flour selection.
These two are among my favorite flours for different reasons and it is hard to pick tapioca vs cassava.
The foremost reason that I like them both is that they have a neutral flavor and mix well with others.
They are made from the same starch, high-carbohydrate tuberous root vegetable cassava.
It is a root vegetable similar to yucca, potato, or taro. Both these flours are gluten-free, nut-free, grain-free they are vegan, paleo and vegetarian friendly.
There has been some negative publicity going on about cassava root having cyanide (which is also found in almonds and spinach) and being toxic. This is true but it is removed during the making of flour and there is no chance of anyone being poisoned when consuming it.
Similarities of Tapioca and Cassava
Top Similarities:
Neutral flavor, that maintains a feel-full effect and non-GMO
Gluten-free, grain-free, nut-free therefore allergen free with a 24-month shelf life
Great for digestion
Excellent source of energy
Low in sodium while still providing vitamins and minerals such as foliate, iron and manganese
Cassava can even substitute tapioca evenly. As I said before they can both be found in kosher, vegan, vegetarian, or paleo kitchens. As you can see they have really good similarities and what sets them apart you may wonder…
What makes cassava flour different from tapioca flour?
Top Differences:
Cassava:
Full cassava root, peeled, dried and ground
Is thicker and has more fiber therefore creating a greater gut health
Slight nuttier flavor
Can substitute easily in wheat flour substitutes
Great for making tortillas and breads
Of other gluten-free flours this is the most easily compatible with wheat flour
Has a greater amount of nutrients, protein, fiber, potassium, calcium, iron, vitamin C, vitamin K, vitamin B6, Folate
As the owner of Gluten-Less Flour I am promoting flour and products that I myself believe in. I believe them to be of good quality and would like to share them. As an Amazon Associate I earn from qualifying purchases, but rest assured that it will by no means change the price of the product. Full Disclosure
Here is a link to the one I use: Amazon
Tapioca:
Starch extracted from the cassava root
Does not have full amounts of nutrients as cassava flour
Stickier quality making it perfect for sauces, pudding, Boba drinks (bubble tea)
Best place to purchase- AMAZON
What are the purposes or strengths of each?
In prior posts as well as this one I have talked about the best uses for these flours. Here is a recap:
Cassava: 
Flat Breads
Tortillas
Pizza Crust
Biscuits
Brownies
Tapioca:
Thickening for sauces
Pie filling
Sauces
Pudding
Bubble tea (Boba)
In conclusion they are both great, with different strengths. Hopefully I was able to teach you the difference and help with your selection.
They are both very useful in the kitchen and can be used in numerous recipes. The strangest part is that although they are made from the same plant they are also very different which instead of putting them against each other in tapioca flour vs cassava flour, it is more of them working along with each other and bringing different strengths into the kitchen.
Sources:
Oboh, G., Akindahunsi, A. A., & Oshodi, A. A. (2002). Nutrient and anti-nutrient contents of Aspergillus niger-fermented cassava products (flour and gari). Journal of Food Composition and Analysis, 15(5), 617-622.
Dufour, D., O’Brien, G. M., & Best, R. (Eds.). (1996). Cassava flour and starch: progress in research and development (No. 271). CIAT.