The best replacement for baking soda is baking powder.

The best alternatives to baking soda are rated as following:
★★★★★  baking powder
★★★  yeast
★★  washing soda
★  powder
★  toothpaste
★  cornstarch
★  bicarbonate of soda
★  salt
★  vinegar
★  soda ash
★  borax
★  sodium bicarbonate
  baking power
  baking powder substitution
  bread soda
  baking soda
  bicarbonate soda
  apple cider vinegar
  cream of tartar
  aluminum oxide
  baking powder in baking
  baking powder substitute
  calcium carbonate
  activated charcoal
  cooking soda
  corn starch

Your alternative for baking soda is not listed? Suggest!
Speaking about baking soda, one probably shouldn't forget about vinegar.

Other search terms related to baking soda and their ratings are:

★★★★★ vinegar
★★★★ shampoo
★★ lemon juice
★★ toothpaste
★★ peroxide to whiten teeth
hard boiled eggs
hydrogen peroxide
baking powder
boiling eggs
maple syrup
face wash
adderall xr
laundry detergent
aluminum cancer
vinegar reaction
cream of tartar
apple cider vinegar
You have in mind a companion for baking soda and it is not yet here? Propose!

Google Trends

Scale is based on the average worldwide traffic of baking soda in all years. Click on graph for more.
baking soda
baking powder