Redfin's home estimate is better than Zillow's Zestimate — but it still has the same fundamental problem. It gives you a number. You can't see how they got it. You can't challenge it. You can't adjust it for what makes your home unique.
ShopProp's CMA tool fixes all three problems.
How Redfin's Estimate Works
Redfin uses its own algorithm combining MLS data, tax records, and market trends. It claims a lower median error rate than Zillow — around 2% for on-market homes. That sounds impressive until you realize 2% of a $1 million home is still $20,000 off.
More importantly, Redfin's estimate is a closed system:
- You can't see which comparable sales it used
- You can't remove outlier comps that don't represent your market
- You can't adjust for condition, view, lot size, or location quality
- You can't add comps it missed
It's a better guess than Zillow's. But it's still a guess you can't verify.
How ShopProp's CMA Tool Works
ShopProp Intelligence takes the opposite approach: total transparency.
Enter any address and you see:
- The 10 closest comparable sales — every one shown with address, price, square footage, lot size, year built, days on market, and price per square foot
- Over/under indicators — instantly see how each comp relates to the subject property
- 7 interactive sliders — adjust for Condition, Location, View, Waterfront, Age/Updates, Lot Size, and Demand
- One-click outlier removal — delete any comp that doesn't represent your market
- The percentage delta — see immediately if a listing is overpriced vs comps
Move a slider and your estimated value recalculates instantly. Remove an outlier and it updates. Add a comp and it factors in. This is how professional appraisers work — now you can do it yourself.
Side-by-Side Comparison
| Feature | Redfin Estimate | ShopProp CMA |
|---|---|---|
| Data source | Proprietary algorithm | 10 closest comparable sales (exposed) |
| Transparency | Hidden formula | Raw price-per-sqft data visible |
| Adjustments | None — static number | 7 interactive sliders |
| Outlier control | None | One-click removal |
| Add your own comps | No | Yes |
| Overpricing detection | No | Yes — shows % above/below comps |
| Cost | Free | Free |
Why This Matters When You're Buying or Selling
For buyers: When you walk into a negotiation with data showing a home is 15% above comparable sales — with the comps visible, the math exposed, and outliers removed — you're not lowballing. You're being precise. That's leverage no Redfin Estimate provides.
For sellers: When you're pricing your home, you need to know exactly where you stand relative to recent sales. Not a mystery number — actual comparisons you can see and adjust for your upgrades, your view, your location advantages.
The Brokerage Behind the Tool
ShopProp isn't just a valuation tool — it's a full-service brokerage with a managing broker on every transaction. Buyer fee starts at $1,995. Seller listing from $4,995.
Redfin charges 1.5% to list (that's $15,000 on a $1M home) and uses salaried agents, not managing brokers.
Same transparency philosophy in our tools and our pricing. No hidden algorithms. No hidden fees.