WordCamp Finland 2015, Page performance optimization

© 1998 PhotoSpin

Average page is 1795 KBin size and growing

WordPress sites are worse

In Finland: WordPress sites average 2,5 MB

Page size matters

Page sizedoes not matter

(that much)

Page size≠

page performance

Page performance ≠

server-side performance

PRACTICAL TIPS

Optimize images

Optimize images for users automatically

Never use the original sizes of uploaded images

Prevent users usingthe full size image

There is a filter for that

function h1_remove_full_image_size( $sizes ) { unset( $sizes['full'] ); return $sizes; }

add_filter( 'image_size_names_choose', 'h1_remove_full_image_size' );

Don’t load imagesa.k.a. lazy loading

Make browserscache resources

Minimize,combine, compress

Minimize,combine, compress

Minimize,combine, compress

Minimize,combine, compress

Advanced stuff

Move scripts to bottom

…with WP Simple Asset Optimizer

Moving scriptsadd_filter( 'wpsao_move', function () { return array( 'jquery_json', 'gform_placeholder', 'gform_gravityforms', 'optin-monster-api-script', 'wp-mediaelement', 'visualizer-google-jsapi', 'visualizer-render' ); } );

Inline CSS and JavaScript

Inliningadd_filter( 'wpsao_inline', function () { return array( 'modernizr', 'h1-stylesheet' => array( 'replace' => '../../', 'with' => get_template_directory_uri() . '/assets/' ) ); } );

Topics skipped: CDNs, responsive and retina images, continuous performance measurement,

inlining images, CSS sprites, server side optimization, prioritizing visible content, avoiding

redirects, DNS, asynchronous JavaScript, HTTP2…

Thanks!

@akibjorklund

Go to akibjorklund.com/wcfi2015 to get all the links mentioned in this talk.