Enable to not load them if you don't support IEs and other oldies, or have polyfills at your theme globally. File sizes approximately in minified gzip. The plus (+) sign refers to dependencies like <code>dblazy.js (~4KB)</code>, etc. A few can be removed via this form. For illustration, Colorbox which is called very lightweight is 4.8KB + jQuery (31KB) = 35.8KB. Blazy never loads all its JavaScript at once, instead conditionally and carefully loads ones as required. Mostly based on your options including these ones. <ul><li><b>Lazyload</b>: remove libraries and loader/ initializer scripts (<code>blazy.js (original: 2.2KB, fork: 1.6KB+), blazy.load.js (1KB+), bio.js (1.7KB+)</code>.) for non-js Native lazy. <br><b>Note!</b> While the above is always valid, a <code>blazy/compat (<1KB + bio.js)</code> and or <code>blazy/dblazy</code> in the least is conditionally loaded as required if any js-dependent options are enabled: <ul><li>Image effect animation or Blur.</li><li>Dynamic multi-breakpoint aka Fluid aspect ratio (excluding fixed ones).</li><li>Dynamic multi-breakpoint (Responsive|Picture based), or static CSS background.</li><li>Local video.</li><li>Loading priority: defer.</li><li>Sub-module requirements. Slick, Splide, Ultimenu, Jumper, etc. might require <code>blazy/dblazy</code>, not a lazyload script, just common jQuery replacement methods for vanilla ones.</li></ul></li><li><b>Polyfills</b>: Only loaded (total 3.6KB) if the above conditions are met, and left unchecked. <b>Basic polyfills</b>: <code>Object.assign, closest, forEach, matches, startsWith, CustomEvent</code>. <b>webp falback</b>: FWIW, IE9, not tested against old Safari, works fine with core/picturefill w/o this fallback. For other polyfills, due to questionabe licenses, include them into your theme as needed such as <a href=':io'>IntersectionObserver</a>, etc. <br><b>Warning!</b> The polyfills may be deprecated and removed when <a href=':cash'>Cash DOM</a> module is available, and will be replaced by Cash accordingly.</li></ul>As of 2022/1, Native only supports IMG and IFRAME, the exceptions above cover BLUR, DIV, VIDEO, ratio FLUID, LOADING: defer, etc. Other JavaScript (Media Player, Lightbox, Non-css Masonry (Flexbox or Nativegrid), etc.) can already be disabled via Formatters since 1.x. jQuery (31KB) is only loaded for Colorbox (4.8KB) + blazy.colorbox.js (1.2KB+) and admin UIs. Details in blazy/js directory. <a href=':url'>Read more</a>.