Cloudflare is a hugely successful American service which combines a reverse proxy with a content delivery network, and throws a host of bonus security and optimisation tools into the technical mix.
The service isn't a conventional CDN. You don't have to choose the specific content you'd like to cache, and there's no need to edit your site code. Instead, you update your DNS nameservers to use Cloudflare, and once the changes have propagated (officially this could take 24 hours, typically it's much less) the service kicks in automatically.
Some of the benefits are similar to other CDNs. Cloudflare detects the location of any visitors and directs them to its nearest data centre. This serves your content from its own cache if possible, improving response times.
Other advantages are more low-level. Because Cloudflare knows all about your web traffic, it can filter it in various ways. The program can block threats based on reputation, HTTP headers, blacklists and more. It can stop or restrict abusive bots, limit comment spam, protect key ports (SSH, telnet, FTP) from hackers, or detect and mitigate DDoS attacks in various ways.
Quality extras include some effective image optimisations. Cloudflare's ‘Polish’ technology works to reduce image file sizes by an average of 35%, while ‘Mirage’ uses multiple techniques to optimise how images are displayed on mobile devices. These features alone could make a huge speed difference to some sites.
While Cloudflare has a strong focus on ease-of-use and consumer-friendly features, the service also offers plenty for the more demanding and technical user. You get support for IPv6, HTTP/2 and SPDY, WebSockets, page rules to manipulate traffic, a REST API, dedicated SSL certificates and more.
The Cloudflare product range starts with a basic free plan. This places strict limits on some features (basic DDoS protection only, just 3 page rules included), and drops others entirely (no image optimisations), but there are no stupid restrictions to try and force you to upgrade. You get the same access to some advanced features, like the REST API, as the commercial accounts. The plan is free forever, too, with no bandwidth limits.
Cloudflare Pro is a $20 (£16) a month account aimed at professional users. This extends the free plan with Cloudflare's Web Application Firewall, throws in the image optimisation tools, and allows up to 20 page rules. The email support gets a median response time of two hours, rather than 13 hours with the free plan. Overall, there's probably enough functionality here to justify the cost, especially for high traffic sites which would be hit with extra bandwidth charges on other CDNs.
Cloudflare Business ramps up the high-end features with advanced DDoS protection, custom SSL certificate upload, optimised delivery of dynamic content, PCI compliance, prioritised support and up to 50 page rules. All this sounds good to us, although we're less convinced by the $200 (£160) a month price tag.
You can extend these plans with a range of add-ons. A dedicated SSL certificate costs only $5 (£4) a month; 5 extra page rules costs $5 (£4); smart routing and load balancing also start at $5 (£4) a month, and rate limiting protects against denial of service attacks, brute-force password attempts and more for $0.05 per 10,000 good requests.
Creating a Cloudflare account works much like any other web service. Enter your email address, choose a password, and that's essentially it.
You start the process of accelerating your first website by entering its domain. Cloudflare grabbed every DNS record we knew existed and a few we didn't, then it provides an option to add more, and allows the user to decide which settings it's going to take over, and which they’ll manage themselves. (If you've no idea, it's usually safe to accept the default settings – they can be changed later, if necessary).
After that, the only remaining step is to set your domain name servers to point at Cloudflare. This requires visiting your domain registrar, web host or whoever else is managing your domain, and following the instructions in their control panel. It will probably take a few hours for the new settings to spread around the web, but there's no downtime; your website will continue working as normal.
This DNS step can't be automated for security reasons, but if you prefer a simpler approach you could use a web host with Cloudflare support, such as UK2. If the host is managing your domain, setup could be as easy as selecting an option in your control panel, or the company might handle it for you.
Cloudflare's web console opens with an Overview page which displays your current site status. This will initially tell you that you have a "DNS modification pending", but eventually the site will be marked as "Active".
The console displays small icons for 12 more function areas, including Analytics, DNS, Firewall, Speed, Caching, Page Rules, Network, Traffic and Customise. Even experts will be left guessing at what might be in some of these, but clicking each one in turn reveals more.
The Analytics area has a stack of detailed reports covering bandwidth usage, requests, DNS traffic, cache effectiveness, unique visitors, threats blocked and more. Even the free plan gets most of these, although there are some significant time-related limits (the DNS report covers the last 6 hours only; the Pro account maintains up to a day).
The Crypto area enables managing your website cryptography, creating and installing SSL certificates and configuring related options. Some of its settings are extremely obvious (you can turn on ‘Always use HTTPS’ with a click). Others require more experience and thought, including options to turn on HSTS or set TLS 1.3 support. But every setting comes with detailed help embedded in the page, and although it won't turn you into a security expert, even novice users will find it handy.
The Caching area has a similar mix of straightforward and more unusual features. There's a button to instantly clear your cache, for instance, just as you'd expect. But there's also an interesting Always Online feature which steps in if your web server goes down, serving pages from the cache where appropriate, and using a custom ‘error’ page for everything else. And a Development Mode switch temporarily bypasses the Cloudflare cache, enabling you to see any updates to your site in real-time.
The Scrape Shield panel has a couple of useful options. In a click or two Cloudflare can obfuscate any displayed email addresses to prevent them being harvested by spammers, and protect your images from being hot-linked by other sites.
There are plenty more settings available, covering DNS, page rules, low-level network configuration, and a host of ‘apps’ to enhance your website: Google Analytics, PayPal buttons, embedded YouTube videos, live chat, NoAdBlock ad-blocking detection, social media buttons and more.
Cloudflare has an impressive feature set, and even the free version contains plenty of power. If we have one concern, it's the way that mission-critical options often sit alongside more standard settings, rather than being hidden away in an ‘Experts Only’ panel. One click in the wrong place could easily break your site, so it's wise to think very carefully before you change anything.
Working out which is the fastest CDN for you is a complicated business. Every service has its own network which might excel in one country, but disappoint in another. A CDN has to match up with your website visitors, too. Top performance in Europe is no use at all if your visitors are mostly from North America.
CDNPerf can point you in the right direction, listing the fastest providers by country, continent or worldwide.
Cloudflare's July 2017 response times rated an average 9th place (out of 24) in North America, which might seem disappointing – until you notice the service achieved second place in Europe and Africa, sixth in Asia, fourth in Oceania and third in South America. That's far more consistent than almost anyone else, and lifted the company to third place worldwide, behind jsDelivr and CDNetworks.
This isn't the whole story. Cloudflare scores highly in the overall figures because it has a very large network with servers across the globe, delivering at least some benefit to a large number of people. But if your website audience comes mainly from one or two countries, the results may be very different. Cloudflare rates a mid-range 12th in the UK, for instance, and 13th in the US.
However Cloudflare performs in your target areas, keep in mind that you may see other speed benefits from its website optimisations. Put it all together and there's a lot of performance boosting potential here, more than enough to justify signing up for the free plan and trying it for yourself.
Cloudflare is easy-to-use and provides loads of features, great security, and effective website optimisations, not to mention a speedy global network which reaches areas other CDNs often miss. That makes it a must for your performance boosting shortlist.
- We’ve rounded up the best CDNs of 2018