Accelerator

SiteBox Accelerator is a proprietary solution that enhances the security and availability of a website. It adds a caching layer that never expires, significantly offloading the server. This solution also makes the website resistant to DDoS attacks, as the Origin server is only needed to generate a response once the cache is invalidated.

SiteBox Accelerator allows for significant acceleration of the website, but it comes with certain limitations, which are described below.

How it works

The SiteBox Accelerator adds another layer of Cache between the Origin Cache and the Edge Cache, which stores the HTML file generated by the server. From this point on, the Origin no longer participates in serving content, because if the Edge Cache expires, the page content is fetched from the Accelerator.

Limitations

Below is a list of the main limitations associated with SiteBox Accelerator:

1. Only responses with the Content-Type: text/html header can be stored in the Accelerator's memory.
2. Only responses with the HTTP 200 OK status can be cached.
3. Only requests sent using the GET or HEAD methods can be processed, all other request methods are blocked, returning an HTTP 405 Method Not Allowed error.
4. No query parameters are passed to the Origin, so when generating cache for the Accelerator, a request to the URL https://example.com/search?page=2 will be passed to the Origin as https://example.com/search, therefore all query parameters must be handled on the browser side.
5. No request headers are passed to the Origin, this is to ensure that the Origin generates the most generic response that can be safely cached and served to all visitors.

Exceptions

By default, SiteBox Accelerator does not cache requests to the /wp-admin and /wp-json areas. Similarly, logged-in users see the normal version of the site, and the above limitations do not apply - such requests are treated as if SiteBox Accelerator was turned off. SiteBox Accelerator exclusions are the same as for Edge Cache except WooCommerce rules.

Additional features

SiteBox Accelerator also provides several additional features that can only be used when the Accelerator is enabled.

103 Early Hints

Activates HTTP/2 103 Early Hints response support. This feature allows servers to pre-emptively push critical resources to clients, optimizing the connection reuse and reducing perceived page load times by preparing the client for upcoming resources.

All meta tags in the head section that contain the rel="preconnect" or rel="preload" attributes are automatically added to the Link header and will be prefetched when SiteBox Accelerator is active.

The use of Early Hints has no negative impact on the site, in case they cannot improve the performance of the site, they will be ignored.

You can read more about 103 Early Hints on the Mozilla Developer Network website.

Image processing

Activates on-the-fly image optimization, compressing images to reduce file sizes without compromising visual quality. This process enhances page load speeds by minimizing bandwidth usage for image files.

With Lossless and Lossy modes, Cloudflare attempts to strip as much metadata as possible. However, Cloudflare cannot guarantee stripping all metadata because other factors, such as caching status, might affect which metadata is finally sent in the response.

When enabled, in addition to other optimizations, Image processing creates versions of images converted to the WebP format.

Off

Image processing is disabled and no compression is applied. Disabling Image processing does not revert previously polished images to original, until they expire or are purged from the cache.

Lossless

The Lossless option attempts to reduce file sizes without changing any of the image pixels, keeping images identical to the original. It removes most metadata, like EXIF data, and losslessly recompresses image data. JPEG images may be converted to progressive format. On average, lossless compression reduces file sizes by 21 percent compared to unoptimized image files.

The Lossless option prevents conversion of JPEG to WebP, because this is always a lossy operation.

Lossy

The Lossy option applies significantly better compression to images than the Lossless option, at a cost of small quality loss. When uncompressed, some of the redundant information from the original image is lost. On average, using Lossy mode reduces file sizes by 48 percent.

This option also removes metadata from images. The Lossy option mainly affects JPEG images, but PNG images may also be compressed in a lossy way, or converted to JPEG when this improves compression.

FAQ