Redfin/Zillow - do they show all homes in the MSL?

[dls]

I'm trying to figure out if Redfin and/or Zillow actually shown all single-familiy homes in an area when a search is made. Is it possible for a realtor to tag a property in the NWMSL as 'no Redfin/Zillow'? Sometimes it seems like I see houses posted at the Edmonds Realty office downtown Edmonds that I don't see on the Redfin site (when the site search is adjusted for location, price, bedrooms, etc). I've been using Redfin to get an idea if there is enough stuff for sale in the south Snohomish county area to make it worth looking to buy, but am now wondering if there is stuff I'm missing because Redfin doesn't show everything available.

[ira s]

If it's a Northwest MLS listing, it'll be on Redfin. My guess is that the Edmonds Realty office might have pictures in the window that are no longer active listings, so wouldn't be current on the MLS, and not likely even currently for sale.

[Renter in Bellevue]