Création des Logiciels de gestion d'Entreprise, Création et référencement des sites web, Réseaux et Maintenance, Conception
seo New mod_pagespeed: cache advances, progressive JPEGs 2013
Seo Master present to you:
By Joshua Marantz, Jan-Willem Maessen, and Bharath Bhushan, PageSpeed Team
When mod_pagespeed launched in November 2010, one of its benefits was to help websites better exploit browser caching by signing URLs with the resource content hash. This improves the user experience coming back to the same site, and navigating within a site.
In mod_pagespeed 1.2 we have released two new features that improve the caching experience for users coming to a site for the first time: canonicalize_javascript_libraries and insert_dns_prefetch. For additional speedups, converting jpegs to progressive format has been added to the Core Filter Set, and the scope of optimization has been extended to include resources served by external servers, even if they are not running mod_pagespeed.
Your web page loads faster when JQuery is preloaded in users' browser
Numerous web sites use common JavaScript libraries such as jQuery and jQuery UI. But when one library is stored on many sites, browsers end up re-downloading that library for each new site – a waste of time and bandwidth. The new canonicalize_javascript_libraries filter in mod_pagespeed finds such libraries on your site and replaces them with links to the equivalent libraries on ajax.googleapis.com. With the optimization, a browser will notice that your site is requesting the library from the same shared library provider as a previous site it visited, and will use the copy in its cache.
It’s possible to do this by hand, but there are a number of reasons why you might prefer to automate the process. Most important is that you may be using third-party code on your web sites that includes some of these libraries. Using canonicalize_javascript_libraries lets you replace these with hosted versions without having to touch third-party code. It also lets you use local, un-minified JavaScript source code for these libraries while you are debugging your site, and then transition automatically to using minified hosted code when you deploy. The filter spots external libraries using a hash signature; we’ve added a new configuration file, pagespeed_libraries.conf, that stores these signatures, so that you can upgrade the signature configuration without disrupting the rest of your apache installation.
Resolving DNS entries early for critical assets saves hundreds of milliseconds
DNS resolution time varies from <1ms for locally cached results, to hundreds of milliseconds due to the cascading nature of DNS. This can contribute significantly to total page load time. Below is a WebPagetest waterfall showing how DNS lookup time can affect page load time.
The new insert_dns_prefetch filter inserts
Improved performance by optimizing external resources and progressive JPEG
In addition to these new capabilities, mod_pagespeed 1.2 can proxy and optimize resources from trusted domains. This feature enables you to optimize resources even from servers that don't run mod_pagespeed. Beyond compressing and cache-extending such resources, this can improve performance of sites running SPDY where the best practices for performance are to serve all resources from the same domain (see mod_spdy).
Further, convert_jpeg_to_progressive is now a ‘core’ filter. Large JPEG images are now transcoded to progressive. This both improves the browser experience and makes such files smaller.
To see more details about the release, check out the release notes and mod_pagespeed download page.
Joshua Marantz runs Google’s PageSpeed team in Cambridge, MA, which is dedicated to making the web faster for everyone. Josh has been working on making software run fast for several decades, at Google and before that on accelerated chip simulation.
Jan Maessen wrote the earliest version of the image and JavaScript filters in mod_pagespeed and has been with the team ever since. Before joining Google, he was a co-designer and library implementer for the Fortress programming language.
Bharath Bhushan works on making website performance better. He has a Masters in CS from IIT Madras, India.
Posted by Scott Knaster, Editor
2013, By: Seo Master
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| Bharath |
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| Jan-Willem |
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| Joshua |
When mod_pagespeed launched in November 2010, one of its benefits was to help websites better exploit browser caching by signing URLs with the resource content hash. This improves the user experience coming back to the same site, and navigating within a site.
In mod_pagespeed 1.2 we have released two new features that improve the caching experience for users coming to a site for the first time: canonicalize_javascript_libraries and insert_dns_prefetch. For additional speedups, converting jpegs to progressive format has been added to the Core Filter Set, and the scope of optimization has been extended to include resources served by external servers, even if they are not running mod_pagespeed.
Your web page loads faster when JQuery is preloaded in users' browser
Numerous web sites use common JavaScript libraries such as jQuery and jQuery UI. But when one library is stored on many sites, browsers end up re-downloading that library for each new site – a waste of time and bandwidth. The new canonicalize_javascript_libraries filter in mod_pagespeed finds such libraries on your site and replaces them with links to the equivalent libraries on ajax.googleapis.com. With the optimization, a browser will notice that your site is requesting the library from the same shared library provider as a previous site it visited, and will use the copy in its cache.
It’s possible to do this by hand, but there are a number of reasons why you might prefer to automate the process. Most important is that you may be using third-party code on your web sites that includes some of these libraries. Using canonicalize_javascript_libraries lets you replace these with hosted versions without having to touch third-party code. It also lets you use local, un-minified JavaScript source code for these libraries while you are debugging your site, and then transition automatically to using minified hosted code when you deploy. The filter spots external libraries using a hash signature; we’ve added a new configuration file, pagespeed_libraries.conf, that stores these signatures, so that you can upgrade the signature configuration without disrupting the rest of your apache installation.
Resolving DNS entries early for critical assets saves hundreds of milliseconds
DNS resolution time varies from <1ms for locally cached results, to hundreds of milliseconds due to the cascading nature of DNS. This can contribute significantly to total page load time. Below is a WebPagetest waterfall showing how DNS lookup time can affect page load time.
The new insert_dns_prefetch filter inserts
<link rel="dns-prefetch"> tags to allow the browser to pre-resolve DNS for resources on the page. The waterfall below shows the improvement after inserting the hints.
<link rel="dns-prefetch"> is supported on Chrome, Firefox and Internet Explorer.Improved performance by optimizing external resources and progressive JPEG
In addition to these new capabilities, mod_pagespeed 1.2 can proxy and optimize resources from trusted domains. This feature enables you to optimize resources even from servers that don't run mod_pagespeed. Beyond compressing and cache-extending such resources, this can improve performance of sites running SPDY where the best practices for performance are to serve all resources from the same domain (see mod_spdy).
Further, convert_jpeg_to_progressive is now a ‘core’ filter. Large JPEG images are now transcoded to progressive. This both improves the browser experience and makes such files smaller.
To see more details about the release, check out the release notes and mod_pagespeed download page.
Joshua Marantz runs Google’s PageSpeed team in Cambridge, MA, which is dedicated to making the web faster for everyone. Josh has been working on making software run fast for several decades, at Google and before that on accelerated chip simulation.
Jan Maessen wrote the earliest version of the image and JavaScript filters in mod_pagespeed and has been with the team ever since. Before joining Google, he was a co-designer and library implementer for the Fortress programming language.
Bharath Bhushan works on making website performance better. He has a Masters in CS from IIT Madras, India.
Posted by Scott Knaster, Editor
2013, By: Seo Master
seo Scaling automatic web optimization with mod_pagespeed and memcached 2013
Seo Master present to you: 
By Jud Porter, Software Engineer, PageSpeed Team
Making your website fast is crucial to creating a great user experience – but doing so can be complicated, with many factors to consider. That’s why we created mod_pagespeed, an open-source Apache module designed to optimize your web pages automatically and easily. We recently introduced our milestone 1.0 release, and today, we’re following it up with the release of mod_pagespeed 1.1.23.1 to our beta channel.
With this release we've reduced server load time and improved utilization for large, multi-server environments. We accomplished this by adding support for memcached (a popular, scalable cache), and improving logging and statistics reporting. With memcached, multiple Apache servers share and fetch the same resources optimized by mod_pagespeed. Logging and reporting have been improved to make it easier to keep track of resource consumption and optimization effectiveness across multiple sites hosted by a single Apache installation. These new features make mod_pagespeed even better for high-traffic sites and network providers hosting many individual websites on their infrastructure.
We’ve also added a number of other new features and optimizations including:
Jud Porter is a software engineer working on mod_pagespeed, an Apache module designed to automatically make websites faster. In his free time he enjoys experimenting with cocktails, brushing up on his foosball game, and discovering obscure music.
Posted by Scott Knaster, Editor
2013, By: Seo Master
By Jud Porter, Software Engineer, PageSpeed TeamMaking your website fast is crucial to creating a great user experience – but doing so can be complicated, with many factors to consider. That’s why we created mod_pagespeed, an open-source Apache module designed to optimize your web pages automatically and easily. We recently introduced our milestone 1.0 release, and today, we’re following it up with the release of mod_pagespeed 1.1.23.1 to our beta channel.
With this release we've reduced server load time and improved utilization for large, multi-server environments. We accomplished this by adding support for memcached (a popular, scalable cache), and improving logging and statistics reporting. With memcached, multiple Apache servers share and fetch the same resources optimized by mod_pagespeed. Logging and reporting have been improved to make it easier to keep track of resource consumption and optimization effectiveness across multiple sites hosted by a single Apache installation. These new features make mod_pagespeed even better for high-traffic sites and network providers hosting many individual websites on their infrastructure.
We’ve also added a number of other new features and optimizations including:
- Improved CSS optimization. CSS media queries are now supported, and the new fallback_rewrite_css_urls filter allows partial optimization of CSS containing unsupported or proprietary extensions.
- The default set of optimizers now includes the flatten_css_imports filter, improving out-of-the-box performance.
- Improved mod_spdy interaction with support for custom mod_pagespeed configuration and filters for SPDY enabled clients. This makes it easier to deploy SPDY on your site, which can significantly decrease page load times.
Jud Porter is a software engineer working on mod_pagespeed, an Apache module designed to automatically make websites faster. In his free time he enjoys experimenting with cocktails, brushing up on his foosball game, and discovering obscure music.
Posted by Scott Knaster, Editor
2013, By: Seo Master
seo Make the web faster with mod_pagespeed, now out of Beta 2013
Seo Master present to you:
By Joshua Marantz and Ilya Grigorik, Google PageSpeed Team
Cross-posted with Google Webmaster Central Blog and other Google blogs
If your page is on the web, speed matters. For developers and webmasters, making your page faster shouldn’t be a hassle, which is why we introduced mod_pagespeed in 2010. Since then the development team has been working to improve the functionality, quality and performance of this open-source Apache module that automatically optimizes web pages and their resources. Now, after almost two years and eighteen releases, we are announcing that we are taking off the Beta label.
We’re committed to working with the open-source community to continue evolving mod_pagespeed, including more, better and smarter optimizations and support for other web servers. Over 120,000 sites are already using mod_pagespeed to improve the performance of their web pages using the latest techniques and trends in optimization. The product is used worldwide by individual sites, and is also offered by hosting providers, such as DreamHost, Go Daddy and content delivery networks like EdgeCast. With the move out of beta we hope that even more sites will soon benefit from the web performance improvements offered through mod_pagespeed.
mod_pagespeed is a key part of our goal to help make the web faster for everyone. Users prefer faster sites and we have seen that faster pages lead to higher user engagement, conversions, and retention. In fact, page speed is one of the signals in search ranking and ad quality scores. Besides evangelizing for speed, we offer tools and technologies to help measure, quantify, and improve performance, such as Site Speed Reports in Google Analytics, PageSpeed Insights, and PageSpeed Optimization products. In fact, both mod_pagespeed and PageSpeed Service are based on our open-source PageSpeed Optimization Libraries project, and are important ways in which we help websites take advantage of the latest performance best practices.
To learn more about mod_pagespeed and how to incorporate it in your site, watch our recent Google Developers Live session or visit the mod_pagespeed product page.
Joshua Marantz is the technical lead for mod_pagespeed. Ilya Grigorik is the Developer Advocate for Make the Web Fast.
Posted by Scott Knaster, Editor2013, By: Seo Master
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| Ilya |
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| Joshua |
Cross-posted with Google Webmaster Central Blog and other Google blogs
If your page is on the web, speed matters. For developers and webmasters, making your page faster shouldn’t be a hassle, which is why we introduced mod_pagespeed in 2010. Since then the development team has been working to improve the functionality, quality and performance of this open-source Apache module that automatically optimizes web pages and their resources. Now, after almost two years and eighteen releases, we are announcing that we are taking off the Beta label.
We’re committed to working with the open-source community to continue evolving mod_pagespeed, including more, better and smarter optimizations and support for other web servers. Over 120,000 sites are already using mod_pagespeed to improve the performance of their web pages using the latest techniques and trends in optimization. The product is used worldwide by individual sites, and is also offered by hosting providers, such as DreamHost, Go Daddy and content delivery networks like EdgeCast. With the move out of beta we hope that even more sites will soon benefit from the web performance improvements offered through mod_pagespeed.
mod_pagespeed is a key part of our goal to help make the web faster for everyone. Users prefer faster sites and we have seen that faster pages lead to higher user engagement, conversions, and retention. In fact, page speed is one of the signals in search ranking and ad quality scores. Besides evangelizing for speed, we offer tools and technologies to help measure, quantify, and improve performance, such as Site Speed Reports in Google Analytics, PageSpeed Insights, and PageSpeed Optimization products. In fact, both mod_pagespeed and PageSpeed Service are based on our open-source PageSpeed Optimization Libraries project, and are important ways in which we help websites take advantage of the latest performance best practices.
To learn more about mod_pagespeed and how to incorporate it in your site, watch our recent Google Developers Live session or visit the mod_pagespeed product page.
Joshua Marantz is the technical lead for mod_pagespeed. Ilya Grigorik is the Developer Advocate for Make the Web Fast.
Posted by Scott Knaster, Editor2013, By: Seo Master
seo Measure and optimize with mod_pagespeed experiments 2013
Seo Master present to you: 
By Jeff Kaufman, Software Engineer, PageSpeed Team
Making your site fast shouldn’t require lots of manual optimization. With mod_pagespeed, an open-source Apache module, you can automatically apply web performance optimization best practices like cache extension, image optimization, and css inlining to speed up your site without a lot of hassle. As of version 0.10.22.4, mod_pagespeed now supports A/B tests integrated with Google Analytics, allowing you to measure how much it speeds up your site on live traffic and experimentally determine the best settings.
When running an experiment, mod_pagespeed randomly assigns visitors to experimental configurations based on percentages you choose. You can run an experiment on 1% of your traffic, 100%, or anywhere in between without affecting other visitors. It also injects JavaScript to report experiment assignments back to your Google Analytics account in a custom variable. Within Analytics you can track the impact of experimental configurations on page load times, bounce rates, conversions, or any other Analytics metric.
We ran an example experiment, comparing mod_pagespeed running with default settings to mod_pagespeed in pass-through mode, on a small blog. This required adding the following lines to our
Average page load time is sensitive to outliers, however, so to better understand the effects it’s helpful to check a histogram:
The clearest change is that mod_pagespeed moved about 7% of page loads from taking 1-3 seconds down to 0-1 second, but there is also an improvement in the long tail.
We encourage you to follow the experiment framework guide and start measuring the effect mod_pagespeed has on your site.
Jeff Kaufman works on mod_pagespeed, an open-source Apache module that helps make the web faster, and is interested in experiment measurement. He also plays for contra dances, organizes other dances, and blogs about dancing, giving, and tech.
Posted by Scott Knaster, Editor
2013, By: Seo Master
By Jeff Kaufman, Software Engineer, PageSpeed Team
Making your site fast shouldn’t require lots of manual optimization. With mod_pagespeed, an open-source Apache module, you can automatically apply web performance optimization best practices like cache extension, image optimization, and css inlining to speed up your site without a lot of hassle. As of version 0.10.22.4, mod_pagespeed now supports A/B tests integrated with Google Analytics, allowing you to measure how much it speeds up your site on live traffic and experimentally determine the best settings.
When running an experiment, mod_pagespeed randomly assigns visitors to experimental configurations based on percentages you choose. You can run an experiment on 1% of your traffic, 100%, or anywhere in between without affecting other visitors. It also injects JavaScript to report experiment assignments back to your Google Analytics account in a custom variable. Within Analytics you can track the impact of experimental configurations on page load times, bounce rates, conversions, or any other Analytics metric.
We ran an example experiment, comparing mod_pagespeed running with default settings to mod_pagespeed in pass-through mode, on a small blog. This required adding the following lines to our
pagespeed.conf:ModPagespeedRunExperiment onWhile this site was static and contained mostly text, it did use some JavaScript and images and had not been manually optimized. We ran the experiment for a month, over which Analytics observed 11K page views, and we saw a 20% improvement in average page load time:
ModPagespeedAnalyticsID "UA-XXXXXXXX-Y"
# half the users get the pagespeed optimizations
ModPagespeedExperimentSpec id=3;percent=50;default
# half get an unoptimized site
ModPagespeedExperimentSpec id=4;percent=50
Average page load time is sensitive to outliers, however, so to better understand the effects it’s helpful to check a histogram:
The clearest change is that mod_pagespeed moved about 7% of page loads from taking 1-3 seconds down to 0-1 second, but there is also an improvement in the long tail.
We encourage you to follow the experiment framework guide and start measuring the effect mod_pagespeed has on your site.
Jeff Kaufman works on mod_pagespeed, an open-source Apache module that helps make the web faster, and is interested in experiment measurement. He also plays for contra dances, organizes other dances, and blogs about dancing, giving, and tech.
Posted by Scott Knaster, Editor
2013, By: Seo Master