Nginx PageSpeed Benefits of ngx_pagespeed

Thought I'd start documenting specific examples where you can benefit from using ngx_pagespeed. While not all web sites, web apps and web designs will have such benefits, you'd have to decide yourself Latest Centmin Mod 123.09beta01 also supports installing ngx_pagespeed as a dynamic Nginx module.

For this forum, a huge benefit for ngx_pagespeed which Centmin Mod Nginx installs and supports (but disabled by default) is for on the fly image optimisations to optimise images for both desktop and mobile and tablet users (yes you can have different levels of optimisations for both types). You can see this forum's pagespeed.conf config file settings at Nginx PageSpeed - This forum's pagespeed.conf | Centmin Mod Community

Some stuff you just can't manually optimise for - auto user uploaded image attachment optimisation and conversion to webp format via ngx_pagespeed

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auto optimised PNG conversion where browser doesn't support WebP

auto optimised conversion of user attachments from PNG to WebP format where browser supports WebP. Almost 88KB size reduction for those 3 images combined by converting on the fly to WebP format. Now imagine 100s of images on your site and with average web page sizes blowing out to nearly 2MB and 80% being related to image size, you can see how ngx_pagespeed can help

excerpt from ngx_pagespeed stats ~52% reduction in image sizes served to visitors

Code:

image_rewrite_total_bytes_saved:                              243473
image_rewrite_total_original_bytes:                           468526

Code:

image_file_count_reduction:                                        0
image_rewrites:                                                   14
image_resized_using_rendered_dimensions:                           0
image_norewrites_high_resolution:                                  0
image_rewrites_dropped_intentionally:                              7
image_rewrites_dropped_decode_failure:                             0
image_rewrites_dropped_mime_type_unknown:                          0
image_rewrites_dropped_server_write_fail:                          0
image_rewrites_dropped_nosaving_resize:                            0
image_rewrites_dropped_nosaving_noresize:                          7
image_rewrites_dropped_due_to_load:                                0
image_rewrites_squashing_for_mobile_screen:                        0
image_rewrite_total_bytes_saved:                              243473
image_rewrite_total_original_bytes:                           468526
image_rewrite_uses:                                             1958
image_inline:                                                   1142
image_webp_rewrites:                                               7
image_rewrite_latency_total_ms:                                 6619
image_ongoing_rewrites:                                            0
image_webp_conversion_gif_timeouts:                                0
image_webp_conversion_png_timeouts:                                0
image_webp_conversion_jpeg_timeouts:                               0
image_webp_alpha_timeouts:                                         0
image_webp_opaque_timeouts:                                        0
in_place_oversized_opt_stream:                                     0
in_place_uncacheable_rewrites:                                     0

If you're using Centmin Mod Nginx with ngx_pagespeed enabled, you can enable pagespeed statistics following the instructions at ngx_pagespeed install on Centmin Mod - Menu based Nginx installer for CentOS servers

Or if you're more comfortable in SSH command line to run would be (provided you have enabled ngx_pagespeed)

Code:

curl -s localhost/ngx_pagespeed_statistics

For ngx_pagespeed message log it's in memory only so no file to view. You'd run SSH commands would be

Code:

curl -s localhost/pagespeed_global_admin/message_history

or

Code:

curl -s localhost/ngx_pagespeed_message

Provided you have properly enabled Pagespeed console as outlined at ngx_pagespeed install on Centmin Mod - Menu based Nginx installer for CentOS servers and enabled MessageBufferSize

Code:

#######################################################
# Set it to 0 if you want to disable this feature.
# pagespeed MessageBufferSize 100000;

enabled

Code:

#######################################################
# Set it to 0 if you want to disable this feature.
pagespeed MessageBufferSize 100000;

restart Nginx web server for it to take effect

As per Nginx Pagespeed Troubleshooting guide at Nginx PageSpeed - Nginx Pagespeed Troubleshooting steps | Centmin Mod Community if you see no permission messages that is normal for 3rd party urls (not your own site hosted).

 

Nice looks like again ~52% image reduction

 

GTMetrix compare between ngx_pagespeed enabled vs disabled results for the Tapatalk installed thread Tapatalk installed on Centmin Mod Community | Centmin Mod Community which has alot of screenshots attached

left = ngx_pagespeed enabled
right = ngx_pagespeed disabled

 

Another example of ngx_pagespeed enabled vs disabled for Oracle Linux 6.5 install guide I wrote which has 33+ image screenshots Vultr - Oracle Linux 6.5 minimal install on Vultr KVM VPS server | Centmin Mod Community

 

webpagetest compare for page at Vultr - Oracle Linux 6.5 minimal install on Vultr KVM VPS server | Centmin Mod Community for ngx_pagespeed enabled vs disabled

a look at initial visual render time (speed index metric) benefits for ngx_pagespeed

 

yeah whenever BD Cache has selective CSS as files that should fix it

 

Yup @RoldanLT linked thread basically has it all laid out for ngx_pagespeed and CDN usage (with SPDY SSL CDN serving)

 

Another example of PageSpeed in action for my thread at Wordpress - Wordpress Auto Installer + WP Super Cache Plugin [Premium Users] | Centmin Mod Community look at the image reductions for auto conversion from png to webp format !

Code:

image_rewrites:                                       142
image_resized_using_rendered_dimensions:                0
image_norewrites_high_resolution:                       0
image_rewrites_dropped_intentionally:                  20
image_rewrites_dropped_decode_failure:                  0
image_rewrites_dropped_mime_type_unknown:               0
image_rewrites_dropped_server_write_fail:               0
image_rewrites_dropped_nosaving_resize:                 0
image_rewrites_dropped_nosaving_noresize:              20
image_rewrites_dropped_due_to_load:                     0
image_rewrites_squashing_for_mobile_screen:             0
image_rewrite_total_bytes_saved:                  1082230
image_rewrite_total_original_bytes:               1455388
image_rewrite_uses:                                 17165
image_inline:                                        4646
image_webp_rewrites:                                   69
image_rewrite_latency_total_ms:                      8852
image_webp_conversion_gif_timeouts:                     0
image_webp_conversion_png_timeouts:                     0
image_webp_conversion_jpeg_timeouts:                    0
image_webp_alpha_timeouts:                              0
image_webp_opaque_timeouts:                             0

 

every bit counts

 

yes it rewrites and optimises jpg too - see Configuring PageSpeed Filters and specifically the following

• convert_jpeg_to_webp
• recompress_jpeg
• recompress_images

 

another example for ngx_pagespeed via webpagetest.org

no ngx_pagespeed



ngx_pagespeed





content breakdown image size dropped from 19,268,838 bytes for 39 images to 2,201,026 bytes for 41 images

no ngx_pagespeed



ngx_pagespeed

 

Looking good and yes 3G mobile can definitely see ngx_pagespeed shine