What Your Home Is Really Worth: Why Online Estimates Vary
If you’ve ever looked up your home’s value online, you’ve probably noticed a curious thing: no two websites agree. One platform might estimate your home at $415,000, while another says it’s worth $435,000 — and yet a third throws out $402,000. These differences can be frustrating, especially when you’re planning to buy, sell, refinance, or tap into your home equity.
So what’s behind these wildly different numbers? The answer lies in how Automated Valuation Models (AVMs) work — and why even the best models still leave room for variation.
What Is an AVM, Anyway?
An Automated Valuation Model (AVM) is a data-driven algorithm that estimates a property’s value based on publicly available information. This usually includes:
- Recent sales data from comparable homes in the area (known as “comps”)
- Property tax assessments
- Public records (square footage, lot size, year built, etc.)
- Neighborhood trends, including school ratings and crime stats
AVMs are designed to be fast, consistent, and scalable — unlike human appraisals, which are more detailed but slower and subjective. That’s why banks, lenders, real estate platforms, and insurance companies all rely on AVMs to estimate property values in real time.
Why the Estimates Vary from Site to Site
Each AVM has its own proprietary algorithm — and each company weighs factors differently. Some put more emphasis on historical sales, while others lean into neighborhood trends or recent market volatility. Here are a few key reasons why home value estimates differ:
1. Data Sources
Some platforms pull data from Multiple Listing Services (MLS), while others rely on public records. If a recent sale hasn’t been recorded yet or the data is outdated, the estimate might be off.
2. Update Frequency
Not all AVMs refresh at the same pace. One model might update daily, while another updates monthly — which can lead to a lag in reflecting recent market changes.
3. Algorithm Complexity
Some AVMs use simple regression models, while others use machine learning to identify patterns. The more advanced the model, the more nuanced the estimate — but even the smartest AI can’t account for what it can’t see (like a renovated kitchen or a neglected roof).
4. Geographic Coverage
Certain AVMs perform better in urban areas where there’s lots of sales data. In rural or low-turnover neighborhoods, estimates can be less reliable due to smaller sample sizes.
The Confidence Score Matters
Many AVMs include a confidence score — essentially a ranking of how certain the model is in its estimate. A high score means the algorithm found a strong set of comparable homes. A low score means there’s more uncertainty, often due to limited data or unusual property characteristics.
It’s always wise to take both the value and the confidence score into account when reviewing an AVM result.
Why Eppraisal Remains a Trusted Source
One of the oldest and most trusted AVM providers in the space is Eppraisal.com. Launched in the early days of online real estate tools, Eppraisal has built its reputation on delivering fast, transparent, and easy-to-understand home value estimates for millions of users.
Unlike some platforms that treat their AVM like a black box, Eppraisal combines data from multiple sources and presents it in a way that empowers users — whether they’re buying, selling, or just curious. It's a helpful starting point for understanding your home's market position, especially when used alongside expert advice from real estate agents and appraisers.
Bottom Line: Use AVMs as a Starting Point
Online estimates are great for getting a ballpark figure of what your home might be worth — but they’re not gospel. Think of AVMs like weather forecasts: helpful, data-driven, but still subject to change.
If you're preparing to list your home or make a major financial move, it’s smart to use multiple AVM tools, check their confidence scores, and consult a professional for a more hands-on evaluation.
After all, no algorithm — no matter how advanced — can walk through your living room and appreciate the natural light, custom tile work, or that killer backyard deck.
Want to know what your home is really worth? Start with a trusted AVM from Eppraisal — then take the next step with confidence.