Treat the portal ratings as a first pass, never the deciding factor. The school ratings baked into the big listing sites are a starting signal. If you're comparing the majors head to head, we'd trust Redfin's data over Zillow's, but we wouldn't stop there for something this consequential. A better resource is greatschools.org, which is nationwide and organizes ratings by school assignment for an address or zip code. In our experience its ratings are reasonably reliable, and we point clients to it regularly. Just remember that assignment boundaries get redrawn, so confirm which schools a specific address actually feeds into rather than assuming. For the most accurate picture, go straight to the source: the local school district's own website for the neighborhood you're considering. The district has the authoritative attendance boundaries, enrollment details, and current information the aggregators may lag on. A good local agent can also tell you how families in the area actually regard the schools, which is context a star rating never captures. Portals for the first pass, greatschools.org to compare, the district to verify. Then let schools inform a six-figure decision.