Site performance
Why a return visit can load differently
The first visit downloads resources that a later visit may already have. Test both experiences before drawing a conclusion.
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Site performance
Understand what loads, what waits and what to measure.
Site performance
Object caching is not another name for page caching
A cache of reusable data works at a different layer from a saved HTML page. Check the hosting support before adding an integration.
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Site performance
Give each optimization job one owner
Map overlapping features before enabling another optimizer. Page caching, file changes and image delivery need clear responsibilities.
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Site performance
Clear the right cache after a visible change
An old page may be stored in several places. Find which copy is stale before repeatedly clearing everything.
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Site performance
Decide whether a CDN solves your visitors' delay
A content delivery network can shorten some delivery paths. It cannot automatically fix every delay in an application.
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Site performance
Check which image size the browser actually downloads
The media library shows available files. The browser decides which candidate it uses for a particular layout.
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Site performance
Choose an image format by the image's job
Photos, small interface labels and transparent graphics do not have identical export needs. Compare the actual output.
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Site performance
Do not make the first useful image wait
Delay images that can wait, while allowing the first useful content to arrive promptly. Check the rendered page rather than a global toggle.
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