Why is Zillows data much lower than other websites?

[Gurjot Grewal]

For looking at median home prices and comparing markets to get a general idea I have been using zillow. But the prices are so off. Dallas for example median home price is 336,973 with data thru july 31st 2022 on zillow. Realtor.com has the median house price at 529k. 

I was using zillow to also use their website to get an estimate for rents. I figured it'd be more accurate to use one site for this information.