HTML optimizations
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Strips whitespace and comments from the HTML output, and minifies inline CSS and JavaScript along with it.Low risk. The rare exception is a theme relying on whitespace inside
<pre> blocks or on HTML comments as markers.toggle
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Keeps the page hidden until it is fully parsed, then reveals it at once. Removes the flash of unstyled content and the layout shifts it causes.This trades LCP for CLS. Nothing is visible until the page is ready, so the largest paint happens later, but it happens in its final position. Try it and compare; whether it helps depends on your theme.
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Pro. Skips rendering blocks and elements until they are needed, reducing the work the browser does on first paint.Tune it with
lightify_lazy_render_skip_count, lightify_lazy_render_limit, and lightify_lazy_render_exclude_keywords.CSS optimizations
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Removes unnecessary characters from your stylesheets. On by default and safe on nearly every site.
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Pro. Loads only the CSS the initial view actually uses, and defers the rest until the visitor interacts.This is usually the largest single improvement available, because most themes ship one stylesheet covering every page and every state.
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Selectors or keywords to force into the generated CSS, one per line. This is your repair tool when removing unused CSS breaks something.The pattern to recognize: anything hidden until the visitor does something. Menus that open on click, modals, dropdowns, accordions, and tabs are all invisible when the page is analyzed, so their styles look unused.
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Pro. Downloads external stylesheets and serves them from your domain, removing a DNS lookup and a connection to a third party. On by default with Pro.
JavaScript optimizations
The two JavaScript settings do different things and are often confused.toggle
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Removes unnecessary characters. On by default.
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Loads scripts without blocking HTML parsing, so the page renders while scripts download.The first setting here with a real chance of breaking things. Scripts that expect to run in order, or expect jQuery to be ready at a specific moment, are the usual failures.
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Scripts to leave alone, one keyword per line. A fragment of the filename is enough.
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Pro. Holds scripts entirely until the visitor moves, scrolls, or taps.The right tool for third-party tags. Analytics, chat widgets, ad scripts, and heatmaps all do work the visitor did not ask for, and delaying them until interaction removes that from your initial load completely.
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Scripts that must not be delayed. Same format as the defer exclusions.
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Pro. Downloads external scripts and serves them locally. On by default with Pro.
Do not self-host a script that is meant to update itself, such as a payment provider’s SDK or a consent manager. Add those to the exclusions, or you will be serving a frozen copy.
Font optimizations
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Tells the browser to fetch essential font files immediately rather than waiting to discover them in the CSS. On by default.
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Pro. Shows a system font immediately and swaps to your custom font when it loads, so text is readable straight away instead of invisible.The tradeoff is a visible swap when the real font arrives, which counts as layout shift if the two fonts have different metrics.
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Pro. Downloads external fonts, most often Google Fonts, and serves them from your domain.Faster, because it removes a third-party connection, and better for privacy, because visitors’ browsers stop contacting the font provider. That second point matters for GDPR compliance in some jurisdictions.
When something breaks
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Purge everything
Cached pages were built with the old settings.
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Identify the feature
Turn off the last one you enabled and purge again.
3
Exclude, do not disable
Add the specific file or selector to the relevant exclusion list. Losing one script from an optimization is much better than losing the optimization.
Progressify
Generatify
Lightify
Rankify
Snapshotify