soft-navigation

Introduction

What a soft navigation is and what the package adds to Lighthouse user flows.

1 min read 1 section

A soft navigation is a route change that updates the URL and the content without loading a new document, like a single page app does on a link click. Stock Lighthouse can't measure one as a navigation step: it waits for a page load that never comes and fails with NO_FCP.

@push-based/lighthouse-soft-navigation is a Lighthouse config that fixes this. With it, a navigation step that stays in the document is measured from the click, with FCP, LCP, TBT, CLS and a Performance score, by Lighthouse's own audits. Page loads, timespans and snapshots run exactly as before.

Requirements

  • Lighthouse 13.6 or newer
  • Chrome 149 or newer, the first version that reports soft navigations in the trace

All pages

  • Getting started Introduction Introduction What a soft navigation is and what the package adds to Lighthouse user flows.
  • Getting started Usage Usage Install the package, measure a soft navigation step and read its result, with Lighthouse or user-flow.
  • Guides Throttling Throttling Why a soft navigation step needs DevTools or provided throttling, per step or for the whole flow.
  • Guides Limits and troubleshooting Limits and troubleshooting What a soft navigation step cannot measure, and what to do when one fails.