Most elementary schools are good if you spend a little time there - be involved, volunteer if you can, get to know the staff. Unless there's a violence issue there or if your kiddo needs a special program, look more at the high school feeder pattern than the elementary ratings. See what class offerings or magnet programs they offer. Will your kids want to learn Russian or go into a medical/vet program? Or will they be happy with Spanish and yearbook?

I think a lot of those ratings are easily skewed if the school has a high esl population so take them with a grain of salt. I've never been in a school that wasn't trying

Niche appears to compare across the country, and greatschools looks to compare with the state. It's likely that a school that greatschools gives a terrible grade might be top tier elsewhere.

As another said, it's also impacted by ESL kids (English as a Second Language).

A good indicator could honestly be looking at their job openings. High turnover or a lot of vacancies could be tell-tale signs of poor administration or a challenging student body. If the school struggles with filling spots that means that there will be a lot of inconsistently with students having subs or teachers leaving mid-year