WebPerf Zopfli Optimization: Literally Free Bandwidth

yeah it's good, I use Zopfli based script to auto compress static files on H20 HTTP/2 web server before they had on the fly compression support

however, for image optimisation of PNGs much easier way with irfanview which i have used for nearly 10 yrs now.

basic optimisation true color original left vs optimised right down to 613.92KB



convert to 256 bit color pallete with best compression - down to 201.32KB



then apply PNGout on than image



end result is this image below at 135.36KB !

 

And if I just take the true color version 32bit and pass through PNGout alone = 561.77KB lossless image



png



the ngx_pagespeed auto png to webp lossless version seems to end up at around 424KB (same as if i saved to webp via irfanview as lossless) but if i use Irfanview to save original as webp it ends up between 83-88KB in size depending on preset used due to maybe quality setting at 75%

 

Irfanview if you got many local images to optimise, use batch conversion



Of course then if you're using Centmin Mod LEMP stack with ngx_pagespeed module enabled, you get further optimisation if possible via auto png to webp conversion for web browsers that support it For this forum, ngx_pagespeed saves around 50% image bandwidth via auto optimisation One of the many benefits of ngx_pagespeed

 

well Firefox 44 is coming this month and it supports brotli compression which compresses between 20-40% better than gzip deflate for text.. already testing this on this forum as I am using Centmin Mod 123.09beta01 with ngx_brotli module enabled. Original details here

brotli > zopfli > gzip

 

curious what discourse's avatar png images (from blog article) will end up like with ngx_pagespeed's auto webp conversion on this forum

Optimize Images | PageSpeed Module | Google Developers

edit: doh ngx_pagespeed auto inlined them instead



but not before converting to webp it seems

 

New web dev & web performance forum to continue image optimisation discussions https://community.centminmod.com/forums/web-development-web-performance.60/