Founded in 2011 to support online gaming, Luxembourg-based G-Core Labs now offers powerful management hosting packages and a very capable, enterprise-level CDN.
G-Core's network covers more than 40 locations across four continents, significantly more than many competitors. The company hasn't just crammed most of them into Europe and North America, either. Russia and CIS countries are covered by fifteen points of presence (PoPs), there are five in Asia, and others in Brazil, Israel, Dubai and Australia.
The core service is a pull CDN, where G-Core automatically grabs files from your servers as they're required. A prefetching feature enables loading files before they're first requested, ensuring users always get the best possible performance. There's optional origin push support (G-Core stores all your content, reducing the load on your server) at extra cost.
Security features include free shared SSL, and the option to use your own custom SSL certificate at no extra cost.
Elsewhere, a strong feature set includes support for HTTP/2 and IPv6. Custom HTTP rules allow you to define exactly how and when content is cached and served, an 'Instant Purge' (which actually takes 'several minutes') feature clears the cache whenever you like, and there's a REST API to help automate any complex tasks.
G-Core is aimed very much at high traffic sites. Even the baseline Startup plan has a minimum charge of $250 (£200) a month, which gets you a bandwidth allowance of up to 5TB.
Still, if you crunch the numbers that's better value than most. It works out at $0.05 per GB, similar to many budget providers, and maybe half the price of Amazon Cloudfront and other big-name services.
There are no annoying hidden catches. G-Core doesn't charge extra for requests, or HTTPS, or transfers from premium regions. Overage rates are the same $0.05 per GB. There are no artificial limits on the number of zones or resources you can create, either – one account can be used to support as many domains as you like.
For us, G-Core's real stand-out feature is its transparency. A Demo Account allows browsing the CDN Control Panel to see the type of reports you'll get, and the settings you can apply. A status page shows you recent network issues. And if that's not enough, there's a free 14-day trial available, no payment details required.
Getting started with G-Core is unusually easy. Hand over your name, company and email address, click the Confirm link in the following email and you're taken directly to G-Core's web console: no hassles at all.
The Control Panel is more intuitive than most, too. It prompts you to create a new CDN resource, default settings are well chosen, and you could start by entering just your origin server (the source domain or IP address).
There's also plenty of control available for more experienced users. The CDN can pull content from a single source or a group, optionally with a custom port. It can connect only via HTTP, only via HTTPs, or choose automatically. You're also able to use a shared SSL certificate, or add a wildcard SSL of your own.
G-Core allows specifying a CNAME, or alternate domain (cdn.mydomain.com). Unusually, you can extend this with a custom origin directory. For instance, you can set this to /images/ and a client request to 'cdn.mydomain.com/pic.jpg' is redirected to 'cdn.mydomain.com/images/pic.jpg'. It's a simple idea, but could be a convenient way to keep your files more organized.
The well-designed interface doesn't assume you're a CDN guru. Jargon is kept to the service basics, text boxes initially display example entries, and there's a caption under each setting to explain exactly what it does. It's both more powerful and usable than most of the competition.
If your needs are simple you might not have much more to do. Tapping the 'Setup Instructions' displays your origin and CDN names, and explains how you must update your website code to have objects pulled from the CDN (use 'cdn.mydomain.com/file.ext' instead of 'www.mydomain.com/file.ext'.) The same page points you to support articles for common issues, and gives you an email link for personal support.
There are more configuration options if you need them. These start with origin shielding, where you can specify a CDN server to handle requests in the event of a cache miss (a simple way to reduce the load on your origin server).
G-Core also provides an extremely powerful Rules dialog. This enables matching URLs with literal text or regular expressions, applying new caching rules, configuring access in various ways (country, IP address, referrer, secure token, user agent, HTTP method and more), adding custom headers, even applying GZIP compression or optimizing the service to deliver large files.
This is by far the most complex set of functions G-Core has to offer. Rule creation isn't fully described in the support pages, and you'll need plenty of CDN and HTTP header experience to understand what's possible. But if that's not an issue, you'll find an enormous amount of power and flexibility available here, which tramples effortlessly over most other services.
Once you're up and running, G-Core's Dashboard keeps you up-to-date with attractive reports on CDN traffic, bandwidth, response codes, cache hit ratio and requests per second. You can filter by time to view anything from the last hour to a full month, or you're able to view aggregated data over the last year.
Advanced Analytics takes reporting even further, with details on cache use by location, directories, devices, browsers, operating systems and more.
Support is available 24/7, including by live chat, email and ticket. We tried the chat service and had accurate and helpful replies to our questions within a couple of minutes, much better than we typically see elsewhere.
Overall, it's a very impressive setup – but you don't have to take our word for it. If you're at all curious, go to the G-Core login page, click Demo Account and you can explore all the screens and reports we've described. There's no need to register or provide any details, you're free to browse as much as you'd like.
Comparing CDNs is a challenge, as there are so many variables to consider: the numbers and locations of your visitors, the size and type of files, how often they're updated, the web applications you're using, and more. Change any element and you could get a different result.
One simple approach is to just look at average CDN response time. It's only a single figure and can't begin to tell you the whole story, but it's still a useful metric which gives a basic idea of how fast a service may appear.
As we write, CDNPerf ranks G-Core as 13th out of 23 for worldwide response times. While that might seem very ordinary, it's only fractionally behind some big-name services (Edgecast, Cloudfront and Fastly are ranked 10, 11 and 12) and just ahead of a few others (KeyCDN, CacheFly, MaxCDN).
Drilling down to continent-level performance reveals similar mid-range scores. G-Core is rated 9th for response times in Europe, 11th in Asia, 17th in North America.
There is one major speed highlight, though. CDNPerf rates G-Core as the fastest responding CDN in Russia. The margin of victory can be huge – G-Core's average response time is currently 27ms, Level3 is 80ms, Fastly 105ms – and the service also scores well in neighbouring countries.
Overall, G-Core offers decent performance which is in line with many other enterprise CDNs. It's difficult to say precisely how it will work for you, but we would recommend taking the free trial to see for yourself.
G-Core is a high-quality service with a stack of features, a well-designed web dashboard and loads of detailed reports and CDN analytics. The $250 (£200) monthly minimum charge is hefty, but if you'll use the 5TB transfer allowance, G-Core is a must for your CDN shortlist.