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Page Load Is Fast Enough On 3G

Why the audit is important

Many mobile users of your page experience the equivalent of a 3G network connection. Ensuring that your page loads fast over a simulated 3G network ensures that your page loads in a reasonable amount of time for your mobile users.

How to pass the audit

There are two main metrics regarding how users perceive load time:

  • The page appears visually complete.
  • The page is interactive. If a page appears visually complete at 1s, but the user can't interact with it until 10s, then the perceived page load time is 10s.

To speed up time-to-visually-complete, only load the resources you need in order to display the page. See Critical Rendering Path and Optimizing Content Efficiency.

To speed up time-to-interactive, only execute the JavaScript that you need in order to display the page, and defer the rest. See Get Started With Analyzing Runtime Performance to learn how to analyze JavaScript execution with Chrome DevTools. Record load performance shows you how to record a page load. Once you're familiar with the basics, do a page load recording and analyze the results to find JS work that can be deferred. See Rendering Performance for strategies.

How the audit is implemented

This section explains how this audit is implemented, so that you can understand how the audit's score is calculated.

Lighthouse throttles the page if the network connection is faster than 3G and then measures the time to first interactive. If the time to first interactive is less than 10s, the audit passes.