How long would it take before the swelling goes down after wisdom teeth removal?

Depends: Depends a lot on the first 3 hours = bite firm on cotton over this extraction site, and use ice on the outside of the face next to the extraction site. Next day use warm moist compresses on the face next to the extraction site. Do not smoke.

Depends: Some of the factors that can affect the degree and duration of swelling following removal of wisdom teeth may include whether or not they were impacted, the experience and technique of the surgeon, whether or not anti-inflammatory meds were administered, your physical status, and how well you follow postop instructions. Generally by the third day postop the swelling will be at its peak.