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Fluid runs Lighthouse scans on your storefront pages and keeps the latest result for each one. Use those results to find what slows a page down, fix it in your theme, and show the difference.

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What Fluid scans

Fluid scans the public storefront page of these items: products, enrollment packs, categories, collections, pages, posts, playlists, and media items. A scan measures the page the way a shopper on a phone loads it, using Google PageSpeed with the mobile form factor. Fluid loads the page once first, so the measurement reads a cached page rather than its first build. A scan measures the live page, so it measures your published theme. Changes in an unpublished theme or a fluid theme dev development theme don’t show up in a scan until you publish them. Fluid queues a scan when you create or update one of these items. Changing your theme doesn’t change the items, so after a theme change you request the scan yourself.

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Read the latest result

Get the latest result for the item behind the page, for example a product:
The result carries three summaries, worked out from the full Lighthouse report that comes with them:
  • Category scores, from 0 to 100, for performance, accessibility, best practices and SEO.
  • Core metrics, such as Largest Contentful Paint, Cumulative Layout Shift and Total Blocking Time, with a good, needs-improvement or poor rating where Lighthouse gives one.
  • Optimization opportunities: the audits that found savings, largest saving first. Start at the top of this list.
Any value can be empty when the run didn’t produce it. When no scan exists yet, the request starts one and tells you to check back. See the reference pages for each item type:

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Fix what the scan finds

Each opportunity has a Lighthouse audit ID. These are the ones a theme most often causes, and the theme fix for each: Large media files slow every page that shows them. Compress images and videos before you upload them to the DAM.

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Scan again and compare

1

Record the starting point

Before you change anything, read the latest result and note its scan time, the performance score, and the core metrics you plan to improve.
2

Publish the fix

Make the change in your theme and publish it, so the live page carries it.
3

Request a scan

The scan runs in the background. Wait a few minutes, then read the latest result again.
4

Check that the result is new

Compare the result’s scan time with the one you recorded. Fluid skips a requested scan when one ran in the last few minutes or the scanner is busy, and then you get the earlier result back. If the time hasn’t changed, request the scan again later.
5

Report before and after

Report the page URL, both scan times, and the before and after values for the performance score and each metric you targeted.
Lighthouse scores vary from run to run. Compare a few scans before you call a small change an improvement.