Where to start: free online estimates and public records

The fastest way to get a rough sense of your home's value is to use a free online tool that pulls from public records and recent sales data. Zillow, Redfin, and Realtor.com all offer estimates (called "Zestimates," "Redfin Estimates," and "Zestimates" respectively) that you can access by entering your address. These tools are free and take less than a minute.

These estimates are based on tax assessments, prior sales of your home, and sales of similar homes nearby. They are usually within 5 to 10 percent of what a home actually sells for, but they can be off by more in neighborhoods where homes sell infrequently or where your house is unusual in some way. The estimates update as new sales data comes in, so checking the same tool a few months later may give you a different number.

You can also look up your home's assessed value directly through your county assessor's office website, which is free and public record. Search "[your county name] assessor" to find the office. The assessed value is what the county uses for property taxes and is often lower than market value, but it is a real number tied to your specific property.

Key Takeaways

  • Free online tools like Zillow and Redfin give you a starting estimate in minutes, though they are typically accurate within 5 to 10 percent.
  • Your county assessor's office publishes your home's assessed value for free online, which is lower than market value but based on official records.
  • A professional appraisal from a licensed appraiser costs $300 to $600 and is the most accurate method if you need a precise number for a loan or sale.
  • Comparable sales in your neighborhood (homes similar to yours that sold recently) are more reliable than estimates if you can find detailed listing information.
  • Your home's value depends on condition, location, recent upgrades, and local market trends, so estimates that do not account for your specific situation will be less accurate.

How comparable sales give you a more grounded picture

If you want to move beyond an algorithm's guess, look at homes similar to yours that sold in the last three to six months in your neighborhood. This is called finding comparable sales or "comps." Real estate websites like Zillow, Redfin, and Realtor.com all show recent sales and listing prices for homes near you, usually sorted by price, size, and sale date.

Focus on homes that are close to yours in square footage, number of bedrooms and bathrooms, lot size, and age. If your home is a 1970s ranch with three bedrooms and two bathrooms on a quarter-acre lot, compare it to other 1970s ranches with three bedrooms and two bathrooms that sold recently nearby, not to a newly built five-bedroom colonial. The closer the match, the more useful the comparison.

Note the sale price, not the listing price — homes often sell for less than they are listed for. Most websites show both, and the sale price is what actually happened. If you find five or six recent sales of truly similar homes, the range of those prices gives you a realistic band for what your home might be worth. If they sold for $280,000 to $310,000, your home is probably somewhere in that range.

When to hire a professional appraiser

A licensed appraiser is a professional trained to estimate home value and is required by law to follow standardized methods. An appraisal typically costs $300 to $600 depending on your home's size and location. You need an appraisal if you are refinancing a mortgage, taking out a home equity loan, or settling a divorce or estate — lenders and courts require an official number from a licensed professional.

If you are simply curious about your home's value or planning to sell in a year or two, an appraisal is usually not necessary. But if you need a defensible, official estimate for a financial or legal reason, it is the right tool. Appraisers inspect the home in person, review comparable sales, and account for condition, upgrades, and local market trends in a formal report.

You cannot usually order an appraisal yourself — your lender orders it if you are refinancing, or your attorney orders it if you are in a legal dispute. If you want an appraisal for your own information, you can contact a local appraisal company directly and ask for an appraisal order, though they may ask why you need it.

What affects your home's actual value

Online estimates and comparable sales are only as good as the data they use. Your home's real value depends on factors that a computer algorithm may not know about. A major renovation, a new roof, or a recently updated kitchen can raise value. Deferred maintenance, foundation problems, or a noisy neighbor can lower it. A home in a neighborhood with rising property values and new development may be worth more than one in a declining area, even if the houses themselves are identical.

If your home is unusual — much larger or smaller than others nearby, on a larger lot, or in a unique condition — estimates will be less reliable. The same is true if your neighborhood has few recent sales. In those cases, comparable sales become more important because they show what actual buyers paid for homes like yours, even if there are not many of them.

Market conditions also matter. In a buyer's market with many homes for sale, prices may be lower. In a seller's market with few homes available, prices may be higher. An estimate from six months ago may be outdated if your local market has shifted.

How to use your home's value for financial decisions

Knowing your home's approximate value helps you make decisions about borrowing, selling, or refinancing. If you want to borrow against your home's equity (the difference between what it is worth and what you owe on your mortgage), you need to know its value. If you are thinking about selling, a realistic value helps you price it correctly and avoid overpricing or underpricing.

For property tax appeals, some homeowners use online estimates or comparable sales to challenge their county's assessed value if they believe it is too high. You would file a formal appeal with your county assessor's office, usually with documentation of comparable sales or a professional appraisal. The process and deadlines vary by state and county.

For insurance purposes, you should insure your home for its replacement cost (what it would cost to rebuild), not its market value. These are different numbers. Talk to your insurance agent about whether your coverage is adequate.

Free tools and resources to check regularly

Zillow (zillow.com), Redfin (redfin.com), and Realtor.com (realtor.com) all let you create a free account and track your home's estimated value over time. You can set up alerts so you are notified when the estimate changes or when comparable homes sell nearby. These tools are free and do not require you to sign up for anything you do not want.

Your county assessor's website is also free and public. Search "[your county name] property appraiser" or "[your county name] assessor" to find it. Most counties let you search by address and view the assessed value, property details, and sometimes recent sales history for your home and nearby properties.

If you are thinking about selling, a real estate agent can provide a comparative market analysis (CMA) for free as part of their job. This is not an appraisal, but it is a detailed look at comparable sales and current listings in your area. Agents have access to the Multiple Listing Service (MLS), which shows all homes listed for sale and recent sales data in your area. You can ask two or three agents for a CMA to get different perspectives.

Why estimates differ and which one to trust

Different tools sometimes give different estimates for the same home. Zillow might say $350,000 while Redfin says $365,000. This happens because they use slightly different data sources, weight recent sales differently, and update at different times. Neither is necessarily wrong — they are both estimates based on incomplete information.

If you see a wide range of estimates (say, $330,000 to $380,000), that is a sign that the data is thin or your home is unusual. In that case, comparable sales and a professional appraisal become more important. If estimates cluster in a narrow range, you can be more confident in that range.

For most purposes, knowing your home is worth somewhere in a range (say, $340,000 to $360,000) is enough. You do not need a single exact number unless you are refinancing or in a legal dispute. The free estimates and comparable sales will get you there.

Frequently Asked Questions

Do online estimates like Zillow's Zestimate actually match what my home will sell for?

Zestimates and similar tools are usually within 5 to 10 percent of actual sale price, but they can be off by more if your home is unusual, your neighborhood has few recent sales, or your home has features the algorithm does not know about. They are a starting point, not a may provide. Comparable sales and a real estate agent's opinion are more reliable if you are actually selling.

Can I use an online estimate to challenge my property tax assessment?

Some counties accept online estimates as supporting evidence in a tax appeal, but most prefer comparable sales data or a professional appraisal. Check your county assessor's website or call their office to ask what documentation they accept for an appeal. The process and deadlines vary by location.

How often do online estimates update?

Zillow, Redfin, and Realtor.com update their estimates as new sales data becomes available, which is usually monthly or quarterly depending on how active your local market is. You can check the same address a few months later and see a different number. Setting up a free account lets you track changes over time.

What is the difference between assessed value and market value?

Assessed value is what your county uses for property taxes and is usually lower than market value. Market value is what your home would sell for on the open market today. Your county assessor's office publishes assessed value for free; market value is what online tools and appraisers estimate.

Do I need an appraisal if I just want to know what my house is worth?

No. Free online estimates and comparable sales will give you a reasonable range. An appraisal is necessary only if a lender requires it (for a refinance or home equity loan) or a court requires it (for a divorce or estate). For general knowledge, the free tools are sufficient.