Short answer: Online home value tools are a good starting point, but they can be off by thousands of dollars. Zillow reports its Zestimate's median error is about 2% for homes on the market but about 7% for homes that aren't listed. On a $350,000 Houston home, 7% is roughly $24,500. For a price you can count on, get a comparative market analysis (CMA) from a local agent who has seen your home.

How online estimates work

Tools like Zillow's Zestimate, Redfin Estimate and others use computer models called automated valuation models (AVMs). They look at:

• Public records: square footage, beds, baths, lot size, tax value
• Recent sales nearby
• Market trends

What they can't see:

• Your updated kitchen, new roof or new HVAC
• Condition issues like foundation problems or an older roof
• Whether your home backs to a busy road, greenbelt or lake
• Flood history, which matters a lot in Houston
• Differences between subdivisions and school zones on the same street

Why different sites give different numbers

Each site uses its own model and data, so it's common to see estimates thousands of dollars apart. That doesn't mean one is "right." It means you need a closer look.

What a local agent's CMA includes

A comparative market analysis is a detailed pricing report. A good one includes:

• Recent sales of truly similar homes nearby, usually from the last 3–6 months
• Active and pending listings, which is your competition
• Expired listings, which show what didn't sell and why
• Adjustments for size, updates, condition, lot and location
• A walk-through of your home to see what the data misses
• A pricing strategy based on current market conditions

CMA vs. appraisal

• CMA: Prepared by an agent, free, used to set your list price.
• Appraisal: Prepared by a licensed appraiser, usually ordered by the buyer's lender, used to confirm the home's value for the loan. Pre-listing appraisals are also an option for a few hundred dollars.

Why accurate pricing matters

• Price too high: Your home sits, buyers wonder what's wrong, and you may end up cutting the price and selling for less.
• Price too low: You could leave money on the table.
• Price right: You attract the most buyers in the first few weeks, when interest is highest.

Get your home's value

Start with our free online tool: get an instant home value estimate. Then contact us for a free, detailed CMA. See current prices in your area in our Houston-area home price report.

Zestimate accuracy figures are nationwide medians as reported by Zillow and vary by area.