Can I use a conditioner instead of a developer? - Quora. No. The developer actually opens up the cuticle and extracts pigment molecules before it adds the color to the hair. It's a crucial part of the process with permanent and Demi permanent hair color.
Can you lighten hair without developer?
You can apply bleach to your hair without developer, but it won't lighten your hair. Oxidation lightens the hair. Developer is hydrogen peroxide. Hydrogen peroxide is water with an extra oxygen.