Page speed & Core Web Vitals.

Field data vs lab data (and why we are honest about it)

Field data comes from Google's Chrome User Experience Report (CrUX): the actual experience of real Chrome visitors to your site over the last 28 days. It is the truest picture, but Google only publishes it for pages that get enough traffic. Most low-traffic local service sites do not have it yet. When that happens, a lot of tools quietly show lab numbers and let you assume they are real-world. We do not. Lab data is a single controlled test that Lighthouse runs on demand, and when field data is missing we say so clearly and show the lab result instead.

The three Core Web Vitals

LCP (Largest Contentful Paint) is how long until the biggest thing on screen, usually your hero image or headline, finishes loading. Good is 2.5 seconds or under. INP (Interaction to Next Paint) is how quickly the page reacts when someone taps a button or link. Good is 200 milliseconds or under. CLS (Cumulative Layout Shift) measures how much the page jumps around as it loads, the annoying effect where you go to tap something and it moves. Good is 0.1 or under. Passing all three is a real ranking and conversion edge.

Why mobile speed is the one that pays the bills

The mobile test simulates a mid-range phone on a throttled connection, which is how most of your customers actually find you. A site can feel instant on your office desktop and still be painfully slow on a phone in a parking lot, and that gap is exactly where local businesses lose calls and form fills. If you only fix one number, fix mobile.

Pro tips

• Test the page people actually land on, often a service or city page, not just the homepage.
• Compress and properly size your images first. Oversized images are the number one cause of a slow LCP on local sites.
• If you have no field data yet, that is normal for a newer or low-traffic site. Use the lab score as your baseline and re-check as traffic grows.
• Re-run the test a couple of times. A single lab run can vary a few points based on network and server load.
• A slow server response time (TTFB) usually points to cheap or overloaded hosting, or a bloated platform like a plugin-heavy build.

How we compare to the paid tools

GTmetrix gates mobile testing and multi-location runs behind PRO ($5 to $50 a month) and caps how many free tests you get. DebugBear and SpeedVitals are paid monitoring products. Ours is free, does both mobile and desktop, shows real Google field data when it exists and clearly-labeled lab data when it does not, and explains every number in plain English instead of a wall of jargon. No account, no credit card.

Frequently asked questions