Jetpack's Site Accelerator Site Accelerator (formerly known as Photon, note: "Photon" is now part of the site accelerator) allows Jetpack optimize the image and provide images and static files (such as CSS and JavaScript) through their global server network CDN, and then help you faster page loads.
How to activate Site Accelerator
- On the control panel of your site, go to Jetpack → Settings → performance.
- Performance and speed section, the "site accelerator enable" switch is slid to the open position.
Works Site Accelerator
image
Image CDN (formerly known as Photon) is a graphics acceleration and editing services. This means that we hosted on our servers from your images, reduce the load on your server, and your readers faster image loading speed.
- The service will filter content, but does not change the information in the database.
- The service is currently only available for image posts and pages, as well as screened by image_downsize filter featured image / thumbnail article.
- The service also applies to old articles and new articles, and can be easily turned on or off.
Static file
our form of content distribution network (CDN), the core WordPress hosting from our servers, static assets (for example, JavaScript and CSS) Jetpack WooCommerce and accompanying, thereby reducing the load on your server.
- It will filter URL of each asset WordPress page loading.
- It is currently available only for WordPress core and WooCommerce accompanying assets Jetpack. It is not supported themes and other plug-ins assets.
Questions
1, how to determine the site of the accelerator the size of the image to be provided?
Accelerator site will see the width and height attributes img elements, and then adjusted to provide the size or width of the element belongs to (whichever is smaller) images.
2, there is no way to retain CDN generated HTML in the "width" and "height" attribute?
We removed the width and height parameters, in order to prevent the adjusted image size of the original image are not simultaneously tilted. When you switch from one subject to another, and the theme of the new narrower than the previous theme, which will be particularly important. One advantage is the ability to automatically adjust the image size, so that the image does not exceed the width of the subject matter supports.
limitation
- No cache invalidation - Currently, the image is "permanent" cache and static assets only for WordPress you are using the public version of Jetpack or WooCommerce. For images, if you want to "refresh" certain images, then you need to change the file name. Adding a random query parameters (generally referred CacheBuster) will not work.
- If you need us to remove some pictures, please contact us and provide direct links to relevant documents displayed on your site. These links will be in i0.wp.com, i1.wp.com or beginning i2.wp.com.
- We will only get from listening on port 80 (HTTP) and port 443 (HTTPS) server, adjust and provide gif, png and jpg image. It covers about 99.99% of the world's Web servers. If you're having trouble, try using jetpack_photon_reject_https filter.
- In most cases, we will not "upgrade" image. If your original image is 1000 pixels wide, but you ask us to revise 5000 pixels, we will continue to provide the original 1000 pixel images for you. The upgraded image quality is often poor, so we hope to avoid this problem.
- If your server will take the time to upload images to our CDN longer than 10 seconds, the upload will time out, your image will be damaged. If this happens, try uploading a different name and the file size smaller image.
Themes and plug-ins can also convert an image using the GET query parameters by Photon API. Developers can access developer.wordpress.com, see Photon API documentation and examples.
This is only available on WordPress.com hosted WordPress sites or sites connected with Jetpack. If you move to a different platform, or disconnected from your site with Jetpack, you need to switch to another image services. Jetpack abuse or violation of terms of service WordPress.com behavior can lead to your site can not be used with the service WordPress.com connection.
References https://jetpack.com/support/site-accelerator/