One nostril is bigger than the other! Can I make it smaller?

Thank you very much for sharing your concerns with us.The harmony between facial parts makes us instinctively recognize the beauty... without knowing it, without defining it, just a perception that surprises and captivates us.In this regard, I suggest perform a Closed Rhinoplasty (without visible scars) to treat the tip, base and nasal bridge.With this procedure you get a delicate nose, better harmonize with your other facial features.Respectfully,Dr. Emmanuel Mallol Cotes.-

Hello and thank you for your question.   The only way to improve nostril asymmetry is through surgery.  Based on your
photograph, you may benefit from a tip refining rhinoplasty. Your surgeon can
accomplish this by trimming, suturing, and reshaping the cartilage in your
lower nose.  Make sure you specifically look at before and after
pictures of real patients who have had this surgery performed by your surgeon
and not just a computer animation system. The most important
aspect is to find a surgeon you are comfortable with. I recommend that you seek
consultation with a qualified board-certified plastic surgeon who can evaluate
you in person.
Best wishes and good luck.
Richard G. Reish, M.D.
Harvard-trained plastic surgeon

You would have to be seen in person but everyone has some nasal and nostril asymmetry.  Best of luck.

Without a base view it is difficult to evaluate your nostril asymmetry which may be secondary to a deviated septum or differences in your ti cartilages. Remember, some degree of asymmetry is normal but if you want to reduce the asymmetry, surgery to straighten your septum or modify your tip cartilages and make the tip narrower will be necessary.