Page.ly has announced a brand new CDN service called PressCDN. Page.ly has partnered with a number of companies in order to provide a global distribution network. The biggest selling point they are pushing is speed. For those that don’t know, CDN stands for Content Delivery Network.
A CDN is a content delivery network that stores copies of your images and site files in locations all around the world. This allows them to be downloaded to your visitor’s computer faster, speeding up the overall load time of your page.
At $9 dollars per month, it’s a cheap way to speed up a website but it’s not cheaper than free. Photon, which is one of the services built into the Jetpack plugin provides CDN capabilities. When enabled, images will be served dynamically from the servers that power the WordPress.com cloud. However, Photon does have its limitations. For example:
- Photon filters content but doesn’t change the info in the database.
- Photon currently only acts on images in posts and featured images (post thumbnails).
- Photon will apply to old posts and new ones alike and can be turned on or off easily.
- No cache invalidations – currently the images are cached “forever”. If you want to “refresh” an image you will need to change the name of the image. Adding random query arguments, commonly known as cachebusters, will not work.
- We only fetch, resize, and serve gif, png, and jpg images from servers that listen on port 80. This is about 99.99% of the web servers in the world.
- We will not “upscale” an image in most circumstances. If your original image is 1000px wide and you ask for us to make it 5000px, we will serve you the original 1000px image. Upscaled images are usually of poor quality and we want to avoid that.
- If your server takes longer than 10 seconds to upload the image to Photon, the upload will time out and your image will appear to be broken. Try to upload a differently-named image with a smaller file size if this happens.
- Animated gifs will probably break if resized or transformed via Photon.
On paper, using any type of CDN is supposed to be beneficial to both the site and its visitors. However, until we see some comparison benchmarks preferably from a third-party comparing speeds and services like PressCDN with Photon, we’ll never know.