What Makes a Website Fast

What Fast Means

Google measures loading speed with Largest Contentful Paint, or LCP. It's the moment the biggest image or block of text on the first screen finishes drawing, and Google treats it as the sign that the page's main content has loaded.

Good is 2.5 seconds or less. Poor is anything over 4 seconds. Google grades a site at the 75th percentile of its visits, so three of every four need to come in under the line (web.dev, updated Sept 4, 2025).

More than half of sites still miss at least one of Google's lines. In 2025, 48% of websites passed all three of Google's Core Web Vitals on phones, up from 36% in 2023 (Web Almanac 2025, HTTP Archive, January 15, 2026). LCP is one of the three. The other two measure how quickly a page answers a tap and how much it jumps around while it loads.

What Speed Is Worth

Portent studied more than 27,000 landing pages on 20 websites. Among the B2B lead generation sites, a site that loaded in 1 second had a conversion rate 3 times higher than a site that loaded in 5 seconds (Portent, April 20, 2022).

Vodafone tested the same idea on its own traffic. Half of its visitors got a landing page whose main content loaded 31% faster, and that half produced 8% more sales (web.dev, March 17, 2021).

Every other layer depends on this one. A visitor who leaves during the load never reads your headline.

Where the Weight Comes From

The median home page on a phone weighed 2,559 KB in 2025. Images were the heaviest part at a median of 911 KB, then JavaScript at 632 KB and fonts at 122 KB (Web Almanac 2025, HTTP Archive, January 15, 2026).

Five Things That Slow Most Sites

1. Images

   Size each image for the screen it lands on and save it as AVIF or WebP. Images below the first screen can wait until the visitor scrolls near them.

2. Fonts

   Every weight and style is its own file, and the median page loads 122 KB of them. This site uses two families trimmed to the characters it needs, and its fonts weigh 52 KB together.

3. Code

   JavaScript is the second-heaviest part of the median page, and the phone has to run all of it after the download finishes. Pages built ahead of time can send little or none.

4. Outside Scripts

   Chat widgets, trackers, ad pixels and video players each load code from another company's server. You can't control how fast those servers answer, so each one needs a reason to be there.

5. Hosting

   A slow server delays every file that follows the first one. Prebuilt pages served from a content delivery network skip most of that wait, because a copy sits close to each visitor.

How to Check Your Own Site

1. Open Google's PageSpeed Insights at pagespeed.web.dev (opens in a new tab) and enter your address.
2. Read the top section first. It shows how real Chrome users experienced your site over the previous 28 days, when Google has enough visits to report (PageSpeed Insights documentation, updated Oct 21, 2024).
3. Find Largest Contentful Paint and compare it with the 2.5 second line.
4. Scroll down to the lab test. It loads the page on a simulated phone and lists what to fix first.

How Jud & Co. Builds for Speed

Every page gets a weight budget, and a check runs each time you publish. These are the rules for this site.

• Pages are built ahead of time and served from Vercel's network.
• Fonts stay under 100 KB in total. They're at 52 KB now.
• No outside scripts on any page.
• Images are sized for each screen and load when they're needed.

Sources

1. web.dev, Largest Contentful Paint (LCP) (opens in a new tab), updated Sept 4, 2025.
2. web.dev, Vodafone: A 31% improvement in LCP increased sales by 8% (opens in a new tab), March 17, 2021.
3. HTTP Archive, Web Almanac 2025, Performance (opens in a new tab), January 15, 2026.
4. HTTP Archive, Web Almanac 2025, Page Weight (opens in a new tab), January 15, 2026.
5. Portent, Site Speed is (Still) Impacting Your Conversion Rate (opens in a new tab), April 20, 2022.
6. Google for Developers, About PageSpeed Insights (opens in a new tab), updated Oct 21, 2024.
7. GoogleChrome on GitHub, Lighthouse throttling documentation (opens in a new tab), checked Sept 27, 2026.