Web Performance and Content Optimisation

CloudFlare takes performance to the next level.

Web performance is not just about moving static files closer to visitors, it is also about ensuring that every page renders as fast and efficiently as possible from whatever device a visitor is surfing from. CloudFlare users can choose any combination of these web content optimization features that take performance to the next level.

CloudFlare helped optimize both front-end and back-end web properties for ZenDesk. Read our case study to learn more.


Rocket Loader

Automatically optimizes your pages to minimize the number of network connections and ensure even third party resources won't slow down page rendering.

Reduced connections

Combines multiple JavaScript files into a single request to avoid the overhead of multiple network requests.

Easy on and off

Each of the many CloudFlare Optimizer services is easy to turn on or off. Want to try one of the services? It is one click to turn on. Want to turn one of them off? It is one click simple.


On-the-fly removal of unnecessary characters from HTML, CSS, and JavaScript.
Saves 20% of a file's size and works without caching so it can support even fully dynamic pages.

Nothing to install

CloudFlare Optimizer is available without any hardware, software or code changes. With a simple change to DNS, you can be up and running in five minutes.

Local storage caching

Uses local storage on modern browsers and mobile devices to intelligently cache the objects needed to best render your site.

Cache header optimization

Automatically adjusts the cache header instructions so browsers will correctly cache the resources of a site to minimize the need for new requests.

Asynchronous resource loading

CloudFlare asychronous resource loading opitmizes your HTML load

Optimizes your HTML so it renders as quickly as possible and without needing to wait for slow scripts like widgets or advertising. Your web pages will feel much snappier.

JavaScript bundling

Combines multiple JavaScript files into a single request to avoid the overhead of multiple network requests.

Browser optimization

Every browser works a bit differently, whether it is Internet Explorer on a PC or Safari on an iPhone. Browser optimization automatically adjusts the way content is delivered based on the particular device accessing the site to maximize speed without affecting the site’s look or features.

Aggressive GZIP

Making a website half as big is as good as making the network twice as fast. Hardware optimized lossless compression reduces the size of all your resources and delivers them compressed even through lazy firewalls that incorrectly claim browsers don’t support GZIP.

See the difference

CloudFlare Rocket Loader makes the Financial Times website (FT.com) faster, in spite of them already using a top-tier CDN to deliver their content.

Ready for mobile

The mobile device market is huge and continues to expand. As we look toward 2017, the number of active mobile devices will grow to over 5 billion. CloudFlare recognizes the high expectations of mobile users and this is why we’ve custom-built a technology (Railgun™, Polish & Mirage, Native Mobile App Acceleration & Security, Custom Cache Key, etc.) that provides seamless mobile experience. CloudFlare empowers web businesses to deliver fast, secure, and device specific content to enhance the experience of mobile users.

Learn more


A content delivery network (CDN) takes your static content and stores a copy closer to your visitors. By moving the content closer to your actual visitor, it takes less time to access the resources, which means the page loads faster. Content delivery networks have been around for the last 15 years. Nearly every large website on the Internet uses a CDN.

Web content optimization (WCO) improves the way the resources on your web page load. Websites are collections of multiple apps, widgets, and tags that include everything from the ad network code inserted on a page to a Twitter Retweet or Facebook Like button. WCO ensures that these resources that make up your web page load optimally. While CDNs have been around a long time, WCO is a newer development and takes performance to another level.

We built our own CDN from the ground up. We used the latest technologies like solid state drives for screaming I/O and Anycast routing and geo load balancing to make it as fast and efficient as possible. But we didn’t want our efforts to make the web faster to stop with the traditional CDN. CloudFlare’s Rocket Loader and other WCO services ensures your page renders as fast and efficiently as possible. By using both CDN and WCO, your site is optimized both at the network and browser level.

Pro features

Session optimization

Automatically detect the pages that are most likely to be accessed during a session from the traffic patterns of all the users visiting a site.


Polish automatically applies both “lossless” and “lossy” image optimization to remove unnecessary bytes from images. On average, image sizes are reduced by 35%.


Mirage insures that images delivered to your visitors are the appropriate size and resolution for their device. Mirage detects screen size and connection speed to deliver the best image for the current browser window, mobile or desktop. Learn more

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