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update imgs to lazy load script with easier to see output in console #36

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merged 1 commit into from
Oct 9, 2023
Merged

update imgs to lazy load script with easier to see output in console #36

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17 changes: 11 additions & 6 deletions README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,8 @@ https://github.com/nucliweb/webperf-snippets/assets/1307927/2987a2ca-3eef-4b73-8
<details>
<summary>Table of Contents</summary>

- [Add snippet to Chrome DevTools](#add-snippet-to-chrome-devtools)
- [Video](#video)
- [Core Web Vitals](#core-web-vitals)
- [Largest Contentful Paint (LCP)](#largest-contentful-paint-lcp)
- [Largest Contentful Paint Sub-Parts (LCP)](#largest-contentful-paint-sub-parts-lcp)
Expand All @@ -47,7 +49,7 @@ https://github.com/nucliweb/webperf-snippets/assets/1307927/2987a2ca-3eef-4b73-8
- [First And Third Party Script Info](#first-and-third-party-script-info)
- [First And Third Party Script Timings](#first-and-third-party-script-timings)
- [Inline Script Info and Size](#inline-script-info-and-size)
- [Inline Script Info and Size Including `__NEXT_DATA__`](#inline-script-info-and-size-including-__next_data__)
- [Inline Script Info and Size Including ```__NEXT_DATA__```](#inline-script-info-and-size-including-__next_data__)
- [Inline CSS Info and Size](#inline-css-info-and-size)
- [Get your `<head>` in order](#get-your-head-in-order)
- [e.g. web.dev](#eg-webdev)
Expand Down Expand Up @@ -340,11 +342,14 @@ console.log(findATFLazyLoadedImages());
List all images that don't have `loading="lazy"` or `[data-src]` _(lazy loading via JS)_ and are not in the viewport when the page loads. This script will help you find candidates for lazy loading.

```js

// Execute it after the page has loaded without any user interaction (Scroll, click, etc)
function findImgCanidatesForLazyLoading() {
function findImgCandidatesForLazyLoading() {
let notLazyImages = document.querySelectorAll(
'img:not([data-src]):not([loading="lazy"])'
);


return Array.from(notLazyImages).filter((tag) => !isInViewport(tag));
}

Expand All @@ -358,10 +363,10 @@ function isInViewport(tag) {
);
}

console.log(
"Consider lazyloading the following images: ",
findImgCanidatesForLazyLoading()
);
// easier to view important data using console.table. use array to define what to show in console output.

console.table(findImgCandidatesForLazyLoadingidatesForLazyLoading(), ["src", "alt", "loading", "fetchPriority", "decoding"])

```

### Find render-blocking resources
Expand Down